Tuesday, May 3, 2016

Ch.1 Atomic Structure and Chemical Bonding - JEE Main Core Revision Points

Importance of  Core Revision Points: Core Revision Points are important because if you remember them strongly, many more points related to them will come out of your memory and help you to answer question and problems. Read them many times and make sure you remember them very strongly.

Sections in the Chapter

1.1 Dual Nature of Radiation
1.2 Dual Nature of Matter - de-Broglie Equation
1.3 Heisengberg's Uncertainty Principle
1.4 Wave Mechanical Model of Atom and Concept of Atomic Orbital
1.5 Quantum Numbers

1.6 Pauli's Exclusion Principles
1.7 Orbital Wave Functions and Shapes of Orbitals
1.8 Electronic Configurations of Atoms
1.9 Chemical Bonding
1.10 Review of Valency Bond Theory

1.11 Molecular Orbital Theory
1.12 Linear Combination of Atomic Orbitals (LCAO) Method
1.13 Relative Energies of Bonding and Antibonding Molecular Orbitals
1.14 Combination of 2s and 2p Atomic Orbitals to form Molecular Orbitals
1.15 Conditions for the Combination of Atomic Orbitals

1.16 Energy Level diagram for Molecular Orbitals
1.17 Rules for Filling Molecualr Orbitals
1.18 Electronic Configurations and Molecular Behavior
1.19 Bonding in Some Diatomic Molecules
1.20 Metallic Bond

1.21 Hybridisation
1.22 Intermolecular Forces
1.23 Hydrogen Bonding



Revision Points for Various Sections in the Chapter


1.1 Dual Nature of Radiation

Einstein in 1905 suggested that light has a dual character - Particle nature as well as wave.

Wave like character of light was proposed by Huygens.  In 1856, James Maxwell proposed that light and other forms of radiation propagate though space in the form of waves and these waves have electric and magnetic fields associated with it. Therefore, the light which is travelling through radiation is said  to be composed of electromagnetic waves.

Planck's Quantum Theory of Radiation



1.2 Dual Nature of Matter - de-Broglie Equation

In 1924, Louis de Broglie suggested that similar to light, all microscopic material particles in motion have dual character.

1.3 Heisengberg's Uncertainty Principle


Uncertainty principle

In 1927, Heisenberg put forward a principle known as Heisenberg’s uncertainty principle.

According it, “it is not possible to measure simultaneously both the position and momentum (or velocity) of a microscopic particle, with absolute accuracy.”

Mathematically, this principle is expressed as:

∆x * ∆p = h/4 π

Where
∆x = uncertainty in position

∆p = uncertainty in momentum

The constancy of the product of uncertainties means that, if the position of the particle is known with more accuracy, there will be large uncertainty in momentum and vice versa.

This uncertainty arises, as all observations are made by impact of light, the microscopic objects suffer a change in position or velocity as a result of impact of light. So there is a disturbance in them due to the measurement.

The principle does not affect the measurement of large objects as in these cases impact of light does not created any appreciable change in their position or velocity.

1.4 Wave Mechanical Model of Atom and Concept of Atomic Orbital


Quantum mechanics or wave mechanics is a theoretical science which deals with the study of the motion of the microscopic objects (like electron) which have both observable wave like and particle like properties.

Quantum mechanics was developed indepdendently in 1926 by Werner Heisenberg and Erwin Schrodinger. In 1927, Schrodinger wave equation was published.

1.5 Quantum Numbers


According to quantum mechanical model or wave mechanical model of atom, orbitals represent regions in space around the nucleus where the probability of finding electrons is maximum. A large number of orbitals are possible in an atom.

To describe each electron in an atom in different orbitals, four quantum numbers are used. They are designated as n,l,ml, and ms.



1. Principal quantum number (n) This quantum number determines the main energy shell or level in which the electron is present. It can have whole number values starting from 1 in an atom.

The principle quantum number indicates the average distance of the electron from the nucleus. If n = 1, it is closest to the nucleus and has lowest energy.

Eariest practice was to number shells as K,L,M,N etc.
Shell with principal quantum number n = 1 is called K.
Shell with principal quantum number n = 2 is called etc.

2. Azimuthal quantum number or angular quantum number (l): This number determines the angular momentum of the electron.

It can have positive integer values from zero to (n-1) where n is the principal quantum number. For each value of n, there are n possible values of l.

For n =3, l has three values: l = 0,1,2

The earlier practice is to designate l as subshell and refer it by letters s,p,d,f,….

l=0 = s; l=1=p; l=2=d, l=3=f etc.

The energy of subshell increases with increasing value of l.

3. Magnetic quantum number ( ml): Magnetic field acts on moving electrical charges. ( from chapters on magnetism in physics syllabus). On revolving electrons external magnetic field of the earth acts. Therefore, the electrons in a given subshell orient themselves in certain preferred regions space around the nucleus. These are called orbitals. This quantum number gives the number of orbitals for given angular quantum number l or in a given subshell.

The allowed values of ml are –l through 0 to +l.

There are (2l+1) values of ml for each value of l.

If l = 0, ml has only one value. ml = 0.

If l = 3, ml has 7 values.
ml = -3,-2,-1,0,1,2,3

4. Spin quantum number (ms) : It is observed that the electron in an atom is not only revolving around the nucleus but is also spinning around its own axis. This quantum number describes the spin orientation of the electron.

The electron can spin in two ways – clockwise and anticlockwise.
Values of +1/2 and -1/2 are given to this quantum number. Its value is not dependent on other quantum numbers.

The orientations of spin are also designated by up and down arrows ↑ ↓.

1.6 Pauli's Exclusion Principles


Pauli's exclusion principle: No two electrons can have all four same quantum numbers

1.7 Orbital Wave Functions and Shapes of Orbitals

1. Spherical shape for s.
2. Dumbbell shape for orbitals of p.
3. Four-lobed shape for orbitals of d.
4. Complex shape for all orbitals of higher sublevels

1.8 Electronic Configurations of Atoms

1. Aufbau principles
2. Pauli's exclusion principle: No two electrons can have all four same quantum numbers
3. Hund's rule of maximum multiplicity

1.9 Chemical Bonding

1. Valency bond theory 2. Molecular orbital theory

1.10 Review of Valency Bond Theory

Valency bond theory was proposed by Heitler and London in 1927 and it was further developed by Linus Pauling.

The basic idea of the theory are:

1. A covalent bond is formed by the overlap of half-filled atomic orbitals of the different atoms.
2. The overlapping atomic orbitals must have electrons with opposite spins.


1.11 Molecular Orbital Theory

This theory was proposed by Hund and Mulliken in 1932. The basic idea of the theory is that atomic orbitals of individual atoms combine to form molecular orbitals.

1.12 Linear Combination of Atomic Orbitals (LCAO) Method

According to LCAO method, the orbitals are formed by the linear combination (addition or subtraction) of atomic orbitals of the atoms which form the molecule.


1.13 Relative Energies of Bonding and Antibonding Molecular Orbitals
1.14 Combination of 2s and 2p Atomic Orbitals to form Molecular Orbitals

2s-orbitals combine by addition and subtraction to form bonding and antibonding molecular orbitals.

1.15 Conditions for the Combination of Atomic Orbitals

Main Conditions for the Combination of Atomic Orbitals

1. The combining atomic orbitals should  not differ much in energies.
2. The extent of overlapping between the atomic orbitals of two atoms should be large.
3. The combining atomic orbitals between the atomic orbitals of two atoms should be large.

1.16 Energy Level diagram for Molecular Orbitals

1.17 Rules for Filling Molecualr Orbitals

1. Aufbau principles
2. Pauli's exclusion principle: No two electrons can have all four same quantum numbers
3. Hund's rule of maximum multiplicity

1.18 Electronic Configurations and Molecular Behavior

The important information conveyed by Electron Configuration of a molecule is:

1. Stability of a molecule
2. Bond Order

1.19 Bonding in Some Diatomic Molecules

1. Hydrogen molecule.

1.20 Metallic Bond

More than 80 elements in the periodic table are metals.
The force which holds together atoms of metals is called metallic bond.

1.21 Hybridisation

Hybridizastion is the phenomenon of intermixing of the orbitals of slightly different energies so as to redistribute their energies and to give new set of orbitals of equivalent energy and shape.

1.22 Intermolecular Forces

In addition to normal covalent bond, ionic bond, and metallic bond, there are weak attractive intermolecular forces which occur in all kinds of molecular solids. These are present in case of non-polar molecules such as H2, O2, CO2, CH4 etc. also.

These are classified as:
i) Dipole-dipole forces
ii) Dipole induced dipole forces
iii) Instantaneous dipole-instantaneous induced dipole forces (called London forces)
iv) Hydrogen bonding

1.23 Hydrogen Bonding

When hydrogen atom is bonded to atoms of highly electronegative elements such as fluorine, oxygen, or nitrogen, the hydrogen atom forms a weak bond with the electronegative atom of the other molecule.


Updated 4 May 2016
First Posted on 23 May 2015

Sunday, May 1, 2016

JEE - Study Guide - 3. Atomic Structure

Text Book
Modern's abc of Chemistry by Dr. S.P. Jauhar for Class XI CBSE

Sections in the Chapter

3.1 Fundamental particles
3.2 Thomson’s Atomic Model
3.3 Rutherford’s Scattering Experiment
3.4 Concept of Atomic Number and Discovery of Neutron
3.5 Developments Leading to the Bohr Model of Atom
3.6 Nature of Light and Electromagnetic Radiation
3.7 Particle Nature of Electromagnetic Radiation and Planck’s Quantum Theory
3.8 Atomic Spectra
3.9 Failure of Rutherford Model
3.10 Concept of Energy Levels or Orbits
3.11 Modern Concept of Structure of an Atom: Quantum Mechanical Model
3.12 Wave Mechanical Model of Atom and Concept of Atomic Orbital
3.13 Quantum Numbers
3.14 Pauli’s Exclusion Principle
3.15 Shapes of Orbitals or Boundary Surface Diagrams
3.16 Energy Level Diagram for Electrons in an Atom
3.17 Electronic Configuration of Atoms


Conceptual Questions with Answers: 35
Additional Numerical Problems for Practice: 8
Revision Exercises
Very Short Answer questions 16
Short Answer Questions 42
Long Answer Questions 3

Competition File
Numerical Problems 20
Objective Questions: 47
Fill in the blanks: 10
True or False: 10


Study Plan

Day 1

3.1 Fundamental particles
3.2 Thomson’s Atomic Model
3.3 Rutherford’s Scattering Experiment

Day 2

3.4 Concept of Atomic Number and Discovery of Neutron
Ex. 3.1 to 3.3
Practice Problems 3.1 to 3.9

Day 3

3.5 Developments Leading to the Bohr Model of Atom
3.6 Nature of Light and Electromagnetic Radiation

Ex. 3.4, 3.5,3.6
P.P. 3.10 to 3.15



Day 4

3.7 Particle Nature of Electromagnetic Radiation and Planck’s Quantum Theory
Ex. 3.7 to 3.16

Day 5
P.P 3.16 to 3.24

Day 6
3.8 Atomic Spectra
Ex. 3.17, 3.18
P.P. 3.25 t 3.27

3.9 Failure of Rutherford Model

Day 7
3.9 Failure of Rutherford Model
3.10 Concept of Energy Levels or Orbits
Ex. 3.19 to 3.23
P.P 3.28 to 3.32

Day 8
Bohr’s Theory and Concept of Quantisation
3.11 Modern Concept of Structure of an Atom: Quantum Mechanical Model
Ex. 3.24 to 3.29
P.P. 3.33, 3.34

Day 9

3.12 Wave Mechanical Model of Atom and Concept of Atomic Orbital

3.13 Quantum Numbers
3.14 Pauli’s Exclusion Principle


Day 10
Ex. 3.30 to 3.33
P.P. 3.35 to 3.37

3.15 Shapes of Orbitals or Boundary Surface Diagrams


Day 11

3.16 Energy Level Diagram for Electrons in an Atom
3.17 Electronic Configuration of Atoms

Day 12
P.P 3.38 to 3.46

Revision Period

Day 13
Conceptual Questions with Answers: 1 to 18

Day 14

Conceptual Questions with Answers: 19 to 35

Day 15
Additional Numerical Problems for Practice: 8

Day 16
Very Short Answer questions 16

Day 17
Short Answer Questions 42

Day 18
Study Competition File

Day 19
Numerical Problems 1 to 10

Day 20
Numerical Problems 11 to 20
Day 21

Objective Questions: 1 to 24

Day 22
Objective Questions: 25 to 47

Day 23

Fill in the blanks: 10

Day 24

True or False: 10


Updated 1 May 2016,  11 Mar 2009

IIT JEE Chemistry - Class XII - Study Guide - 3. Solutions

Sections in the Chapter

3.1 Types of solutions
3.2 Methods for expressing the concentration of a solution: units of solution
P.P. 3.1 to 3.20
3.3 Solubilioty of gases and solids in liquids
3.4 Vapour pressure of solutions
3.5 Ideal and Nonideal solutions
P.P. 3.21 to 3.27
3.6 Colligative properties
3.7 Relative lowering of vapour pressure
P.P. 3.28 to 3.34
3.8 Elevation in boiling point
P.P. 3.35 to 3.40
3.9 Depression in freezing point
3.41 to 3.48
3.10 Osmosis and osmotic pressure
P.P. 3.49 to 3.57
3.11 Electrolytic solutions – Abnormal molar masses
P.P. 3.58 to 3.68


Additional Numerical Problems for Practice: 21

Conceptual Questions with Answers: 29
Key facts to remember
Additional Numerical Problems for Practice: 8
Revision Exercises
Very Short Answer questions 21
Short Answer Questions 66
Long Answer Questions 21

Competition File
Numerical Problems 29
Multiple choice questions: 40
Fill in the blanks: 10
True or False: 10


Study Plan

May 26 to 30

Day 1

3.1 Types of solutions
3.2 Methods for expressing the concentration of a solution: units of solution

Day 2

P.P. 3.1 to 3.20

Day 3
3.3 Solubility of gases and solids in liquids
3.4 Vapour pressure of solutions
3.5 Ideal and Nonideal solutions

Day 4

P.P. 3.21 to 3.27
3.6 Colligative properties
3.7 Relative lowering of vapour pressure
P.P. 3.28 to 3.34

Day 5

3.8 Elevation in boiling point
P.P. 3.35 to 3.40

June 1 to 10

Day 6
3.9 Depression in freezing point
3.41 to 3.48

Day 7
3.10 Osmosis and osmotic pressure
P.P. 3.49 to 3.57

Day 8
3.11 Electrolytic solutions – Abnormal molar masses
P.P. 3.58 to 3.68

Day 9

Additional Numerical Problems for Practice: 21


Day 10
Conceptual Questions with Answers: 29

Day 11
Key facts to remember
Additional Numerical Problems for Practice: 8

Day 12
Revision Exercises: Very Short Answer questions 21

Day 13
Revision Exercises: Short Answer Questions 1 to 3366

Day 14
Revision Exercises: Short Answer Questions 34 to 66

Day 15
Competition File: Numerical Problems 1to 20

June 11 onwards

Revision Period
Day 16
Competition File: Numerical Problems 21to 29

Day 17
Multiple choice questions: 1 to 20

Day 18
Multiple choice questions: 21 to 40

Day 19
Fill in the blanks: 10

Day 20
True or False: 10

Day 21 to 30
Concept revision, formula revision, Test paper problem solving



________________

________________
ExamFearVideos

35 parts parts are there more can be there.


Playlist 35 parts
________________

________________


Updated 1 May 2016,  3 Jan 2016, 11 March 2009

JEE - Study Guide - 2. Solid State



JEE Syllabus (2015)

Solid State: Classification of solids: molecular, ionic, covalent and metallic solids, amorphous and crystalline solids (elementary idea); Bragg’s Law and its applications; Unit cell and lattices, packing in solids (fcc, bcc and hcp lattices), voids, calculations involving unit cell parameters, imperfection in solids; Electrical, magnetic and dielectric properties.





Jauhar, CBSE XII class

Sections in the Chapter

2.1 Space Lattices and Unit Cell
2.2 Close Packing in Crystalline Solids
2.3 Interstitial Sites or Interstitial Voids
2.4 Types of Cubic Crystals and Number of Atoms per Unit Cell
2.5 Experimental Methods of Determining Crystal Structure: X Rays Diffraction
2.6 Coordination Number and Radius Ratio
2.7 Ionic Radii
2.8 Calculation of Density of a Crystal from its Structure
2.9 Strctures of Ionic Compounds
2.10 Imperfections in solids
2.11 Properties of solids
2.12 Amorphous solids



Additional numerical problems for practice 12
Conceptual Questions with Answers: 13
Key facts to remember
Revision Exercises: Very Short Answer questions 40
Short Answer Questions : 50
Long Answer Questions : 6

Competition File
Some useful facts
numerical problems 9

Objective Questions: Multiple choice 25
Fill in the blanks: 10
Matching type question 1

Study Plan

Day 1

2.1 Space Lattices and Unit Cell
2.2 Close Packing in Crystalline Solids
2.3 Interstitial Sites or Interstitial Voids

Day 2
2.4 Types of Cubic Crystals and Number of Atoms per Unit Cell
Practice problems 2.1 to 2.3

Day 3

2.5 Experimental Methods of Determining Crystal Structure: X Rays Diffraction
P.P. 2.4,2.5
2.6 Coordination Number and Radius Ratio
P.P. 2.14 to 2.17

Day 4

2.7 Ionic Radii
2.8 Calculation of Density of a Crystal from its Structure

Day 5
P.P. 2.8 to 2.19

Day 6

2.9 Structures of Ionic Compounds
P.P 2.20 to 2.25

Day 7
2.10 Imperfections in solids
2.11 Properties of solids
2.12 Amorphous solids

Day 8


Concept revision
Additional numerical problems for practice 12

Day 9


Conceptual Questions with Answers: 13
Key facts to remember

Day 10

Revision Exercises: Very Short Answer questions 40

Revision period

Day 11
Revision Exercises:Short Answer Questions : 1 to 15

Day 12
Revision Exercises:Short Answer Questions : 16 to 30

Day 13
Revision Exercises:Short Answer Questions : 31 to 50

Day 14

Competition File
Some useful facts
numerical problems 9

Day 15

Objective Questions: Multiple choice 25

Day 16
Fill in the blanks: 10
Matching type question 1

Day 17 to 20

Concept revision and test paper questions/problems




Updated   1 May 2016,  6 June 2015
Originally published 11 March 2009

Saturday, April 9, 2016

Chemistry Knowledge History - April




Chemistry History
http://web.lemoyne.edu/~giunta/April.html





April 1
Claude Cohen-Tannoudji born 1933: cooling of atoms by interactions with laser light; Nobel Prize (physics), 1997.

G. N. Lewis's article, "The Atom and the Molecule," containing Lewis dot structures is published in the Journal of the American Chemical Society, 1916 (April issue, nominal publication date April 1).

Sergei Nikolaevich Reformatskii (Reformatsky) born 1860: synthesis of organozinc halides (Reformatsky reaction).

Julian Stone reported in Applied Physics Letters that a new quartz fiber filled with tetrachloroethylene may be able to carry light, 1972.

Richard Adolf Zsigmondy born 1865: explained heterogeneous nature of colloidal suspensions; introduced the ultramicroscope for study of colloids; Nobel Prize, 1925. View Zsigmondy's book Colloids and the Ultramicroscope.

April 2
Carl Alsberg born 1877: food chemistry;

Francis Crick and James Dewey Watson mailed brief article on the double-helix structure of DNA to Nature in 1953; view a typescript of the article.

Charles Martin Hall obtains US patent 400,766 for an electrolytic process for producing aluminum in 1886.

April 3

First meeting of the Electrochemical Society of America (now simply the Electrochemical Society), at the Manufacturers' Club, Philadelphia.

April 4

Otto Folin born 1867: clinical chemistry; Folin-Wu reagent for glucose analysis.

Johan Peter Klason born 1848: lignin chemistry.

Raoul Pierre Pictet born 1846: liquefaction of oxygen.

Ira Remsen was awarded the first Priestley Medal in 1923.

Synthesis of vitamin B6 announced by Merck, Sharp & Dohme in 1939.

April 5

Richard Chenevix born 1774: mineralogist; chemistry of platinum (Pt, element 78) and palladium (Pd, 46).

Norman Davidson born 1916: ion channels and neurotransmitters.

Marshall Gates and Gilg Tschudi announced synthesis of morphine, 1956.

Joseph Lister born 1827: antiseptics such as carbolic acid (phenol); read part of his report.

April 6

First official organizational meeting of the American Chemical Society held at New York University in 1876.

Edmond Henri Fischer born 1920: protein phosphorylation and its role in biological regulation; Nobel Prize (medicine), 1992.

Feodor Lynen born 1911: biosynthesis of cholesterol; Nobel Prize (medicine), 1964.

Richard Macy Noyes born 1919: chemical kinetics; oscillating chemical reactions.

Roy Plunkett accidentally polymerized Freons producing polytetrafluoroethylene, better known as Teflon (US patent 2,230,654), 1938.

James Walker born 1863: hydrolysis, ionization constants, and amphoteric electrolytes with organic compounds.

James Dewey Watson born 1928: double-helix structure of DNA; Nobel Prize (medicine), 1962.
April 7

Louis Frederick Fieser born 1899: organic chemistry (synthesis and aromatic compounds); invented napalm; coauthor (with wife Mary) of Reagents for Organic Synthesis

Louis Plack Hammett born 1894: physical organic chemistry; structure-activity relationships;
Hammett equation for linear free-energy relationships

Heinrich Hlasiwetz [auf Deutsch] born 1825: protein analysis.

New law established metric system and nomenclature in France, 1795.

Joseph Priestley left England to move to the United States, 1794. A mob hostile to his politically and religiously liberal views had destroyed his home and made him unwelcome in Birmingham.

Walter Stockmayer born 1914: statistical mechanics and dynamics of polymers.

April 8

Melvin Calvin born 1911: research in photosynthesis; Nobel Prize, 1961.

August Wilhelm von Hofmann born 1818: coal tar; organic nitrogen chemistry, particularly dyes; founding president of the German Chemical Society.

Joseph Kenyon born 1885: organic chemistry, stereochemistry and mechanism of nucleophilic substitution.

April 9

F. Albert Cotton born 1930: inorganic chemistry and chemical bonding (metal carbonyls, metal-metal bonds); 1998 Priestley Medal.

Dorothy Anna Hahn born 1876: chemical valence;

Ignacio Tinoco, Jr., proposed a simple method for deducing secondary structure of ribonucleic acid (RNA) from nucleotide sequence, 1971.

Elizabeth Kreiser Weisburger born 1924: investigation of chemical carcinogenesis at the molecular level;

April 10

Arnold Beckman born 1900: chemist and inventor; founder of Beckman Instruments (now Beckman Coulter). View US patent 2,058,761 for pH meter.

Arnold Collins made the synthetic rubber called polychloroprene (also known as neoprene), 1930.

Marshall Warren Nirenberg born 1927: cracking the genetic code (i.e., correlation of nucleic-acid sequence to protein structure); Nobel Prize (medicine), 1968.

Robert Burns Woodward born 1917: stereoselective organic synthesis; synthesis of natural products;

Woodward-Hoffmann rules on orbital symmetry; Nobel Prize, 1965.


April 11

Percy Lavon Julian born 1899: synthesis of physostigmine; preparation of cortisone (US patent 2,752,339).


Hugh Christopher Longuet-Higgins born 1923: multicenter bonds in boranes and other compounds; conjugation.

Ernest Volwiler and Donalee Tabern received US patent number 2,153,729 for sodium pentothal as a general anaesthetic, 1939.

Robert Burns Woodward and William von Eggers Doering reported a formal synthesis of quinine in 1944.

April 12

Marie Curie watched as one of her professors, Gabriel Lippmann, presented her exhaustive survey of radioactivity in natural substances, which presents evidence for substances much more radioactive than uranium, 1898.

Otto Fritz Meyerhof born 1884: muscle metabolism; Nobel Prize (Medicine), 1922.

Thomas Thomson born 1773: early advocate of Dalton's atomic hypothesis and Prout's hypothesis; edited Annals of Philosophy.  History of Chemistry

Georges Urbain born 1872: codiscoverer of lutetium (Lu, element 71); discovered the law of optimum phosphorescence of binary systems.

April 13

Torbern Bergman confirmed Müller von Reichenstein's finding that the substance isolated from a bismuth ore was a new element, tellurium (Te, element 52), 1784.

Michael Stuart Brown born 1941: cholesterol metabolism and its regulation; Nobel Prize (medicine), 1985.

April 14

Alan MacDiarmid born 1927: conducting polymers; Nobel Prize, 2000.

NASA's Nimbus III weather satellite made first civilian use of nuclear batteries (radioisotope thermoelectric generators), 1969.

April 15

Johann Balmer published the observation that certain spectral frequencies of hydrogen are related by a simple mathematical formula (Balmer series), 1885.

William Cullen born 1710: noted the cooling effects of evaporation and of gas expansion.

Catherine Clarke Fenselau born 1939: mass spectrometry and its application to biochemistry; Garvan Medal, 1985.

Albert Ghiorso announced the discovery of Rutherfordium (Rf, element 104) with coworkers (Ghiorso at right) at the University of California, Berkeley, in 1969.

Robert Gore born: inventor of Gore-Tex fabric (waterproof fabric that "breathes") from expanded polytetrafluoroethylene; Perkin Medal, 2005. US patent Patent 3,953,566.

Carol Greider born 1961: telomerase; Nobel Prize (medicine), 2009.

Nikolai Nikolaevich Semenov born 1896: chemical kinetics; theory of chain reactions; Nobel Prize, 1956.

Ernest Solvay received patent entitled "Industrial Production of Sodium Carbonate by Means of Marine Salt, Ammonia, and Carbon Dioxide" (Solvay process) in 1861.

April 16

Joseph Black born 1728: latent heat and specific heat; foundation for modern quantitative analysis.

Marie Maynard Daly born 1921: first African-American woman to earn a Ph.D. in chemistry (Columbia University, 1948)

Humphry Davy performed first physiological experiment on nitrous oxide by inhaling it, 1799. (Don't try this at home!) Read his report.

Albert Hofmann discovered the hallucinogenic effects of lysergic acid diethylamide (LSD), 1943. (Link to US National Drug Intelligence Center's LSD Fast Facts.)

Ernest Solvay born 1838: chemical manufacturer and Belgian government minister; Solvay process for sodium carbonate production.
Sidney Gilchrist Thomas born 1850: effected the separation of phosphorus from iron in the Bessemer converter.

April 17

First oil well fire, at Little and Merrick well, Oil City, PA, 1861.

Robert Robertson born 1869: explosives; amatol (ammonium nitrate/TNT); infrared spectroscopy.
April 18

Marston Taylor Bogert born 1868: synthesis of quinazolines and thiazoles.

Joseph Leonard Goldstein born 1940: cholesterol metabolism and its regulation; Nobel Prize (medicine), 1985.

George Herbert Hitchings born 1905: pharmaceutical chemistry; Nobel Prize (medicine), 1988.

Eugene Jules Houdry born 1892: commercial catalytic cracking of petroleum for gasoline production (Houdry process, first patent application in France; US patent 1,837,963) and catalytic cleaning of automobile exhaust.
Paul-Émile Lecoq de Boisbaudran born 1838: discovered gallium (Ga, element 31), dysprosium (Dy, 66), and samarium (Sm, 62).
William Albert Noyes, Jr., born 1898: editor of Journal of the American Chemical Society, 1950-1962.
Joseph Priestley ignited a mixture of "inflammable air" (hydrogen) and common air, 1781, and noted that the explosion was not as powerful as can be obtained from gunpowder. He failed to recognize (as Cavendish, Lavoisier, and Watt did soon afterwards) that the two gases combine to form water.

April 19

Samuel Cox Hooker born 1864: sugar chemistry
Antoine Lavoisier claimed the right to the discovery of oxygen (O, element 8), arguing that he and Joseph Priestley discovered the same facts, but that he recognized the role of oxygen in combustion while Priestley explained it in terms of phlogiston theory, 1776. (This claim is treated fictionally in the play Oxygen by Carl Djerassi and Roald Hoffmann.)
Ines Hochmuth Mandl born 1917: biochemical basis of pulmonary emphysema; medicinal uses of collagenases, elastases, and their inhibitors; Garvan Medal, 1982
Monsanto incorporated, 1933.
François-Charles-Léon Moureu born 1863: organic chemistry; oxidation and antioxidants; first president of IUPAC.
Glenn Theodore Seaborg born 1912: codiscoverer of plutonium (Pu, element 94), americium (Am, 95), curium (Cm, 96), berkelium (Bk, 97), californium (Cf, 98), einsteinium (Es, 99), fermium (Fm, 100), mendelevium (Md, 101), nobelium (No, 102), and seaborgium (Sg, 106) (named by his coworkers); Nobel Prize, 1951.

April 20

Franz Karl Achard born 1753: introduced platinum crucible; invented process for extraction of sugar from sugar beets and opened the first beet sugar factory.
American Chemical Society organized, 1876, in New York City.
Wilhelm (or Guglielmo) Körner born 1839: isomerism in substituted benzenes (ortho, meta, and para).
Karl Alexander Müller born 1927: high-temperature superconducting materials; Nobel Prize (Physics), 1987.
Gertrude Perlmann born 1912: protein biochemistry, particularly phosphoproteins; Garvan Medal, 1965.
Kai Manne Siegbahn born 1918: electron spectroscopy; son of 1924 Nobel laureate X-ray spectroscopist Karl Siegbahn; Nobel Prize (physics), 1981.

April 21

Jean-Baptiste Biot born 1774: discovered optical activity; Biot-Savart law in electromagnetism.
Percy Williams Bridgman born 1882: effect of pressure on materials; showed that viscosity increases with high pressure; Nobel Prize (Physics), 1946.
Paul Karrer born 1889: synthesis of vitamins A, B2 (riboflavin), and E (tocopherol); Nobel Prize, 1937.
Nalco incorporated as National Aluminate Corporation, 1928.
Pfizer incorporated, 1900.

April 22

Donald James Cram born 1919: Nobel Prize, 1987, for synthetic molecules which imitate biomolecules.
First modern use of chemical weapons: chlorine gas at Ypres, 1915.
First Earth Day, 1970.

April 23

Max Planck born 1858: thermodynamics, particularly second law; introduced quantum theory and constant now known as Planck's constant; Nobel Prize (physics), 1918.

Rohm & Haas incorporated, 1917.

April 24

Roger Kornberg born 1947: genetic transcription in eukaryotic organisms; Nobel Prize, 2006.
Jean de Marignac born 1817: discovery of ytterbium (Yb, element 70) and gadolinium (Gd, element 64). Read some of Marignac's opinions on Prout's law and on atomic and equivalent weights (1 and 2).
Russell born 1898: invented klystron tube, founded Varian instruments (now Varian, Inc.) with brother Sigurd Varian.

April 25

Wolfgang Pauli born 1900: Pauli exclusion principle; Nobel Prize (Physics), 1945.
http://iit-jee-chemistry.blogspot.com/2008/01/iit-jee-ch3-atomic-structure-core.html

"Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid," by James Watson and Francis Crick, published in Nature, 1953.

April 26

Michael Smith born 1932: oligonucleotide-based, site-directed mutagenesis of DNA; Nobel Prize, 1993.

April 27

Philip Hague Abelson born 1913: codiscovered neptunium (Np, element 93).

Wallace Carothers born 1896: macromolecules; invented nylon (US patents 2,130,947 and 2,130,948). Link to lab exercises in making nylon.

Andrew Fire born 1959: RNA interference - gene silencing by double-stranded RNA; Nobel Prize (Medicine), 2006.
Albert Ghiorso (at right) and coworkers announced in 1970 discovery of element 105 (eventually named dubnium, Db) produced by bombarding californium-249 (249Cf) with nitrogen-15 (15N).
Charles James born 1880: separation of rare earth elements.

Antoine Lavoisier reported in 1775 that heated mercury forms red calx (HgO), while the surrounding air is reduced in volume and no longer supports combustion; heating the calx liberates oxygen.

April 28

Alfred Bader born 1924: founder of Aldrich Chemical (now part of Sigma-Aldrich)
Karl Barry Sharpless born 1941: catalytic oxidation, particularly stereoselective oxidation (e.g. Sharpless epoxidation), in organic synthesis; Nobel Prize, 2001

April 29

Atlantic Richfield Company incorporated, 1870.
Nashua incorporated as Nashua Card, Gummed and Coated Paper, 1904.
Harold Clayton Urey born 1893: isolated heavy water (D2O); co-discoverer of deuterium (2H); Nobel Prize, 1934.

April 30

Albert Ghiorso and coworkers announced the discovery of mendelevium (Md, 101) at the University of California, Berkeley, 1958.

Joseph John Thomson announced in 1897 the discovery of a body lighter than all known elements and a constituent of them all--the electron.  Thomson's  Nobel Prize address.

JEE Chemistry - May Study Topics with Links


JEE Main 2018 - (2016 - 2018) Study Plan
http://liit-jee.blogspot.com/2016/04/jee-main-2018-2016-2018-study-plan.html

JEE - Study Guide - 1. Some basic concepts of chemistry
http://iit-jee-chemistry.blogspot.com/2009/03/jee-study-guide-1-some-basic-concepts.html

1

Video Lectures 1.1 Importance of Studying Chemistry
http://iitchemvideos.blogspot.com/2016/04/video-lectures-11-importance-of.html

Video Lectures 1.2 Physical quantities and their S.I. Units
http://iitchemvideos.blogspot.com/2016/04/video-lectures-12-physical-quantities.html

Video Lectures 1.3 Dimensional Analysis
http://iitchemvideos.blogspot.com/2016/04/video-lectures-13-dimensional-analysis.html

JEE - Study Guide - 1. Some basic concepts of chemistry

Chapter 1 of Modern Chemistry for Class XI by Dr. S.P. Jauhar

Contents

1.1 Importance of Studying Chemistry
1.2 Physical quantities and their S.I. Units
1.3 Dimensional Analysis
1.4 Measurement and Significant Figures
1.5 Chemical Classification of Matter
1.6 Laws of Chemical Combination
1.7 Dalton Atomic Theory
1.8 Avogadro's Hypothesis
1.9 Atoms and Molecules
1.10 Atomic and Molecular Mass
1.11 Mole Concept
1.12 Mass-Mole Conversions
1.13 Percentage Composition and Molecular Formula
1.14 Stoichiometry of Chemical Equations
1.15 Stoichiometric Calculations
1.16 Limiting Reactant
1.17 Solution Stoichiometry
1.18 Stoichiometry of of Reactions in Solutions

The chapter is 100 pages

Study Plan

Basic plan is that each chapter is to be completed in 20 days. First 10 days theory portion is to be completed. Next 10 days, some revision of theory portion is to be done and some problems have to be done. In total 20 days all problems in the chapter have to be done. You have to mark all problems which you feel are difficult problems for a revision at a later date and for examinations.

Day 1

1.1 Importance of Studying Chemistry
      Video Lectures 1.1 Importance of Studying Chemistry
1.2 Physical quantities and their S.I. Units
      Video Lectures 1.2 Physical quantities and their S.I. Units
1.3 Dimensional Analysis
      Video Lectures 1.3 Dimensional Analysis

Ex. 1.1 to 1.5

Day 2

1.4 Measurement and Significant Figures
Ex. 1.6 to 1.14
Practice Problems 1.1 to 1.5


Day 3

1.5 Chemical Classification of Matter
1.6 Laws of Chemical Combination
Ex. 1.15 to 1.19
Practice Problems 1.9 to 1.12

Day 4

1.7 Dalton Atomic Theory
1.8 Avogadro's Hypothesis
1.9 Atoms and Molecules
1.10 Atomic and Molecular Mass

Ex. 1.20 to 1.23
Practice Problems 1.17 to 1.20

Day 5
P.P 1.21 to 1.25
P.P 1.26 to 1.30

Day 6

1.11 Mole Concept
Ex. 1.24 t0 1.25
1.12 Mass-Mole Conversions
Ex. 1.26 to 1.32

Day 7
Ex. 1.33 to 1.44

Day 8
P.P 1.31 to 1.45


Day 9

1.13 Percentage Composition and Molecular Formula
Ex. 1.45 to 1.52

Day 10
P.P. 1.46 ot 1.53
1.14 Stoichiometry of Chemical Equations

Day 11
Ex. 1.52 to 1.54
P.P. 1.54 to 1.55

Day 12
1.15 Stoichiometric Calculations

ex. 1.55 to 1.71

Day 13
P.P. 1.56 to 63
1.16 Limiting Reactant
Ex. 1.72 to 1.73

Day 14

1.17 Solution Stoichiometry
Ex. 1.74 to 1.80
P.P. 1.64 to 1.70

Day 15
1.18 Stoichiometry of Reactions in Solutions
Ex. 1.81 to 1.84
P.P. 1.71 to 1.75


Revision Period

Day 16

Conceptual Questions with Answers: 1 to 23

Day 17
Additional Numerical Problems for Practice: 1 to 10

Day 18

Additional Numerical Problems for Practice: 11 to 20

Day 19
Revision Exercises: Very Short Answer questions: 1 to 15

Day 20
Revision Exercises: Very Short Answer questions: 16 to 30

Day 21
Revision Exercises :Short Answer Questions 1 to 10

Day 22
Revision Exercises :Short Answer Questions 11 to 20



Day 23
Competition File: Illustration Problems: 1 to 5

Day 24
Competition File: Numerical Problems: 1 to 8
Day 25
Competition File: Numerical Problems: 9 to 16
Day 26
Competition File: Numerical Problems: 17 to 25
Day 27
Competition File: Objective Questions: 1 to 20
Day 28
Competition File: Objective Questions: 21 to 40

Day 29
Fill in the blanks: 10
True or False: 10

Day 30
Concept Review
Formula Review



Problems have to be included

Monday, February 8, 2016

IIT JEE Ch. 4. PERIODICITY OF PROPERTIES OF ELEMENTS - Revision Points

Importance of  Core Revision Points: Core Revision Points are important because if you remember them strongly, many more points related to them will come out of your memory and help you to answer question and problems. Read them many times and make sure you remember them very strongly.


JEE Syllabus

No specific syllabus on this topic

Study Guide for the chapter - 20 day plan
http://iit-jee-chemistry.blogspot.in/2009/03/jee-study-guide-4-classification-of.html
------------

I want to paste the periodic table in this post. It is important to know the atomic numbers of many elements as well as the group wise elements and periodwise elements. Many times, the answers to questions can be given if we know to which group the elements in the question belong to by analogy to the behaviour of popular elements like Na, Mg, C,N,O,S, and F.

So periodic table is an essential revision


4.1 Development of Periodic Table
4.2 Atomic Number and Modern Periodic Law
4.3 Electronic Configuration
4.4 The long Form of the Periodic Table
4.5 Division of Elements into s, p, d, and f-Blocks
4.6 Periodic Properties
4.7 Atomic Radii
4.8 Ionic Radii
4.9 Ionization Enthalphy
4.10 Electron Gain Enthalpy
4.11 Valency



4.1 Development of Periodic Table

Mendeleeve's Periodic Table Video
10.4 minutes
_________________

_________________
ExamFearVideos


In 1869, Russian chemist Dmitry Mendeleev gave a law known as the periodic law based observations of physical and chemical properties of various elements known to exist at that time.

The law states that: "the physical and chemical properties of elements are periodic functions of their atomic masses."

4.2 Atomic Number and Modern Periodic Law

In 1942, Moseley, physicist of England discovered a relationship between X-ray spectra and the atomic number of elements.

The equation is SQRT(v) = a(z - b)

Where v is the frequency of the X-ray emitted by an elements and z is its atomic number.  a and b are constants.

He suggested atomic number as the basis of classification of elements.
Modern periodic law may be stated as: "the physical and chemical properties of elements are periodic function of their atomic numbers.

4.3 Electronic Configuration
4.4 The long Form of the Periodic Table
4.5 Division of Elements into s, p, d, and f-Blocks

s-block elements: The elements in which the last electron enters the s-orbital of their outermost energy level are callsed s-block elements.

4.6 Periodic Properties
4.7 Atomic Radii
4.8 Ionic Radii
4.9 Ionization Enthalphy
4.10 Electron Gain Enthalpy
4.11 Valency


Updated on  8 Feb 2016,  21 May 2015
First Published on 19 Jan 2008

Chemistry Knowledge History - February





February 1 - Chemistry Knowledge History

Birthdays

Emilio Segrè (1905): codiscovered technetium (Tc, element 43) and astatine (At, 85); spontaneous fission; antiproton; Nobel Prize (Physics), 1959
http://iit-jee-chemistry.blogspot.in/2007/12/chapter-13a-halogens.html  Astatine is a halogen.

Roger Yonchien Tsien (1952): green fluorescent protein, GFP; Nobel Prize, 2008.

February 2 - Chemistry Knowledge History



1923 Leaded gasoline first marketed in the US in Dayton, OH,
1923. Thomas Midgley, Jr., of General Motors Research labs added tetraethyllead to gasoline.

Birthdays

Jean Baptiste Boussingault 1802: agricultural chemistry; isolated and named sorbitol; role of nitrogen in plant nutrition.

Albert Schatz  1920: discovery of antitubercular agent streptomycin. Schatz's version of the discovery differs from the standard account in which Selman Waksman receives near-exclusive credit. The patent (US 2,449,866).

February 3 - Chemistry Knowledge History

Birthdays
Leonora Neuffer Bilger  1893: asymmetric nitrogen compounds; Received Garvan Medal in 1953
https://en.wikipedia.org/wiki/Leonora_Bilger

February 4  - Chemistry Knowledge History

Joseph Goldberger begins the experiment that demonstrates that pellagra is a dietary disease, 1915.


John Jacob Livingood made radium E (210Bi) by bombarding common bismuth with deuterons, 1936, the first synthetis of a radioactive substance in the US.

Birthdays

Friedrich Hund born 1896: Hund's rules for electron configurations, the first of which predicts maximum multiplicity of spin; molecular-orbital theory (Hund-Mulliken approach).
IIT - JEE  http://iit-jee-chemistry.blogspot.in/2015/05/ch1-atomic-structure-and-chemical.html

February 5  - Chemistry Knowledge History

Birthdays - 5 Feb

John Boyd Dunlop (1840); manufactured pneumatic rubber tires.

Lafayette Benedict Mendel  (1872): modern science of nutrition; codiscovered vitamin A and B complex; linked nutritive value of proteins to their amino acids.

February 6  - Chemistry Knowledge History


William Parry Murphy born 1892: diabetes; pernicious anemia and other blood diseases; Nobel Prize (Medicine), 1934
Clemens Winkler, in the course of analyzing a mineral, discovered element (germanium, Ge, element 32) in 1886, consistent with predictions by J. A. R. Newlands and Dmitrii Mendeleev.
Nikolai Dmitrievich Zelinskii born 1861: catalysis of hydrocarbon disproportionations; bromination of fatty acids (Hell-Volhard-Zelinsky reaction)

February 7  - Chemistry Knowledge History


Ulf Svante von Euler born 1905: identification of noradrenaline (norepinephrine) as a neurotransmitter; son of 1929 Nobel laureate biochemist Hans von Euler-Chelpin; Nobel Prize (medicine), 1970.
John Brown Francis Herreshoff born 1850: manufacture of sulfuric acid

February 8 -  - Chemistry Knowledge History


Robert Holton announces total synthesis of taxol, an important cancer drug, 1994.


Birthdays

Bernard Courtois  1777: discovered iodine (I, element 53) from seaweed
Friedlieb Runge born 1795: discovered carbolic acid (phenol) and aniline in coal tar; dry distillation

                                                    Source: Google Doodle of 8 Feb 2016


Dmitrii Mendeleev born 1834 : periodic law and periodic table.
http://iit-jee-chemistry.blogspot.in/2008/01/iit-jee-ch-4-periodicity-of-properties.html
http://www.telegraph.co.uk/technology/2016/02/07/who-was-dmitri-mendeleev-and-how-did-he-order-the-periodic-table/


Francis Robert Japp  born 1848: benzil, benzoin, and phenanthraquinone.
Moses Gomberg born 1866: work on triphenylmethyl (first stable organic free radical); tautomerism





February 9

 - Chemistry Knowledge History


Edward Charles Baly born 1871: showed that organic compounds, including sugars, can be formed photochemically from water, carbon dioxide, and ammonia
Californium (Cf, element 98) discovered by  Kenneth Street, Jr., Stanley G. Thompson, Glenn T. Seaborg, and Albert Ghiorso using ion-exchange chromatography at University of California, Berkeley, 1950.
Lloyd Ferguson born 1918: chemical educator
Norman Bruce Hannay born 1921: materials for solid state electronics

February 10

 - Chemistry Knowledge History


Per Teodor Cleve born 1840: discovered holmium and thulium; suggested "didymium" was not elementary; naphthalene derivatives.
John Franklin Enders born 1897: showed polio virus was not only neurotropic; Nobel Prize (Medicine), 1954.
Ira Remsen born 1846: prominent American organic chemist; founder of American Chemical Journal; first professor of chemistry at Johns Hopkins University; saccharin was discovered in his lab

February 11

 - Chemistry Knowledge History

Fred Basolo born 1920: organometallics.
Thomas Alva Edison born 1847: inventor (incandescent light (US 233,898), phonograph (US 200,521, electrical systems, etc.).
Josiah Willard Gibbs born 1839: thermodynamics and the phase rule; the Gibbs free energy is named after him.
Izaak Kolthoff born 1894: analytical chemistry.
Alwin Mittasch  and Christian Schneider filed US patent application for catalytic production of methanol from carbon monoxide and hydrogen (U.S. patent 1,201,850) in 1914.
William Henry Fox Talbot born 1800: photography pioneer.

February 12

 - Chemistry Knowledge History


Pierre-Louis Dulong born 1785: discovered nitrogen trichloride; refractive indices and specific heats of gases; law of Dulong and Petit (specific heat times atomic weight is the same for many elements); suggested that acids were compounds of hydrogen; formula for heat content of fuel (Dulong formula)

Moritz Traube born 1826: physiological chemist; semipermeable membranes, sugars, respiration, fermentation, putrefaction, oxidation, protoplasm, and muscle

February 13

 - Chemistry Knowledge History


Heinrich Caro born 1834: Caro's acid (H2SO5), dye chemistry.
Étienne-François Geoffroy born 1672: chemical affinities; displacement reactions in salt
Henry Clemens Pearson born 1858: rubber scientist and editor; see his books, Crude rubber and compounding ingredients and The rubber country of the Amazon

February 14

 - Chemistry Knowledge History



Herbert Aaron Hauptman born 1917: mathematical methods for crystal structures; Nobel Prize, 1985.
Lawrencium (Lr, element 103) was produced in 1961 by Torbjorn Sikkeland, Albert Ghiorso, and Almon Larsh and Robert Latimer, at University of California, Berkeley.
Julius Nieuwland born 1878: synthetic rubber pioneer (US patent 1,811,959); acetylene chemistry. .
Agnes Pockels born 1862: liquid surfaces: surface tension and films; invention of the slide trough and surface film balance. Read her article on surface tension.
Dennis Searle and E. M. Skillings found borax and other soluble salts near San Bernardino, CA, 1873.

February 15

 - Chemistry Knowledge History


Synthesis of diamond by Francis Bundy, H. Tracy Hall, Herbert Strong, & Robert H. Wentoff, Jr., at General Electric Research Laboratories announced in 1955.

Hans K. A. S. von Euler-Chelpin born 1873: enzymes and fermentation; father of 1970 Nobel laureate Ulf Svante von Euler; Nobel Prize, 1929

George Johnstone Stoney born 1826: suggested that electrical charge came in discrete units; coined term electron for "atom of electricity".

February 16

 - Chemistry Knowledge History


Julius Thomsen born 1826: heats of reaction, relative strength of acids, manufacture of soda from cryolite
John Rex Whinfield born 1901: terephthalic acid polyester fibers (terylene).

Robert Williams born 1886: isolation, synthesis, and manufacture of Vitamin B1 (thiamine).

February 17

 - Chemistry Knowledge History


Friedrich Konrad Beilstein born 1838: his standard reference work on organic chemistry was first published in 1880-83 and has been updated ever since

Wallace Henry Coulter born 1913: instrument maker; developed instrumentation to characterize particles.
Dmitrii Mendeleev sketched his first draft periodic table, 1869.

Otto Stern born 1888: quantization of angular momentum (Stern-Gerlach experiment); Nobel Prize (physics), 1943.


February 18 - Chemistry Knowledge History

Harry Brearley born 1871: development of stainless steel
John Sinfelt born 1931: platinum-iridium catalysts in petroleum refining. Read a book chapter by Sinfelt on materials and catalysis.
Frederick Soddy introduced the term "isotopic" (meaning "same place") for elements which share the same place in the periodic table in 1913.

Alessandro Volta born 1745: invented the voltaic pile, the first electric battery; discovered and isolated methane. The unit of electric potential, the volt, is named in his honor.
(18 February 2015 - Google carries doodle in the honour of Volta)




http://electronics.howstuffworks.com/everyday-tech/battery4.htm

The Voltaic Pile
_________________

_________________

Science Online

February 19

 - Chemistry Knowledge History


Svante Arrhenius born 1859: electrolytic dissociation, viscosity, reaction rates, and even the greenhouse effect; Nobel prize, 1903

Louis-Georges Gouy born 1854: interfacial electrical double layer.
Gottlieb Sigismund Kirchhof born 1764: catalytically produced glucose from starch.
Roderick MacKinnon born 1956: structural and mechanistic studies of ion channels; Nobel Prize, 2003
Ernest Marsden born 1889: scattering of alpha particles (work with Hans Geiger in Ernest Rutherford's lab), contributing to the development of the nuclear model of the atom.
One atom of mendelevium (Md, element 101) was produced by Gregory R. Choppin, Glenn Seaborg, Bernard G. Harvey, and Albert Ghiorso in 1955 by bombarding a billion atoms of 253Es with helium.
Ferdinand Reich born 1799: codiscovered indium (In, element 49)

February 20

 - Chemistry Knowledge History


Isaac Adams, Jr. born 1836: pioneer in nickel plating.
Ludwig Boltzmann born 1844: statistical mechanics; thermodynamics, especially the second law; Maxwell-Boltzmann distribution of molecular speeds; Stefan-Boltzmann law of blackbody radiation; Boltzmann constant is named after him

Henry Eyring born 1901: chemical kinetics (transition-state theory, Eyring equation)
Helen Murray Free born 1923: diagnostic chemistry: reagents and instrumentation for clinical diagnosis in blood and urine chemistry, histology, and cytology
Robert Huber born 1937: three-dimensional structure of proteins involved in photosynthesis; Nobel Prize, 1988

February 21

 - Chemistry Knowledge History


Carl Henrik Dam born 1895: vitamin K as a dietary factor in blood clotting; Nobel Prize (medicine), 1943.
Humphry Davy reads paper introducing the name chlorine (to replace oxymuriatic acid) and asserting its elementary nature, 1811.

Oliver Wolcott Gibbs born 1822: early American inorganic and analytical chemist (Harvard); founding member of US National Academy of Sciences
Edwin Land demonstrates Polaroid camera to optical society meeting, 1947.
John Mercer born 1791: treated cotton with caustic soda (mercerized cotton); discovered some calico dyes
Dorothy Virginia Nightingale born 1902: synthetic organic chemistry, particularly reactions of alkylbenzenes in the presence of aluminum chloride; Garvan Medal, 1959

February 22

 - Chemistry Knowledge History


Johannes Nicolaus Brønsted born 1879: acid-base theory and properties of ions; kinetics and catalysis; nitramide

Heinrich Hertz born 1857: discovered electromagnetic waves and the photoelectric effect.
Pierre Jules Cesar Janssen born 1824: astronomical spectroscopy and photography, particularly of the Sun; found a line in the solar spectrum subsequently identified with helium.
Fritz Strassmann born 1902: nuclear fission.
Friedrich Wöhler wrote a letter to J. J. Berzelius stating that he had synthesized urea, an early synthesis of an organic compound from inorganic materials, 1828.

February 23

 - Chemistry Knowledge History


First organizational meeting of the Chemical Society of London, 1841. (The Royal Society of Chemistry is its successor organization.)

Casimir Funk born 1884: discovered vitamins and named them (vitamines)
Charles Martin Hall first produced electrolytic aluminum in 1886 (US patent 400,766).
Thomas Midgley, Jr., received US patent 1,573,846 for tetraethyllead as an anti-knock agent in gasoline, 1926.
Glenn Theodore Seaborg and coworkers chemically identified plutonium (Pu, element 94) at University of California, Berkeley, 1941.

February 24

 - Chemistry Knowledge History


First atom of element 107, eventually named Bohrium (Bh) was observed at GSI Laboratories, Darmstadt, Germany in 1981.

John Gorham born 1783: wrote Elements of Chemical Science, an early American chemistry text.
Karl Graebe born 1841: organic synthesis (alizarin) and nomenclature (ortho, meta, para prefixes).
Eugène Melchior Peligot born 1811: isolated uranium metal; identified glucose in diabetics' urine.
William Summer Johnson born 1913: synthesis of complex molecules

February 25

 - Chemistry Knowledge History


Ruth Erica (Leroi) Benesch born 1925: oxygen-carrying capacity of hemoglobin; role of sulfur in proteins
Arthur Becket Lamb born 1880: editor of the Journal of the American Chemical Society, 1917-1949.
Phoebus Aaron Theodor Levene born (as Fishel Aaronovich Lenin) 1869: biochemistry, hexosamines, and stereochemistry.
Ida Eva Noddack born  1896: co-discoverer of rhenium (Re, element 75) with husband Walter and Otto Berg; suggested (correctly) that nuclear fission rather than transuranic elements explained results reported by Enrico Fermi.
Mary Locke Petermann born 1908: ribosomes and protein synthesis

February 26

 - Chemistry Knowledge History


Marjorie Beckett Caserio born 1929: physical organic chemistry: kinetics and mechanisms; chemical education: Basic Principles of Organic Chemistry
Benoit Paul Emile Clapeyron born 1799: relationship between temperature, volume, and heat of vaporization (Clapeyron and Clausius-Clapeyron equations).
Herbert Henry Dow born 1866: electrolytic production of bromine; founder of Dow Chemical.
Giulio Natta born 1903: polymer chemistry including polymer stereochemistry; Nobel Prize, 1963
William Joseph Sparks born 1905: advances in synthetic rubber.
Ahmed Zewail born 1946: "femtochemistry" (dynamics on a sub-picosecond time scale); Nobel Prize, 1999

February 27

 - Chemistry Knowledge History


James Chadwick's note announcing the possible discovery of the neutron is published in Nature, 1932.

Robert Grubbs born 1942: metathesis reactions and catalysts; Nobel Prize, 2005.
Alice Hamilton born 1869: occupational medicine; hazards of carbon monoxide, mercury, tetraethyllead, benzene, and others; first woman professor at Harvard.
Felix Hoffmann received US patent 644,077 for acetyl salicylic acid (better known as aspirin), 1900.
Karl Friedrich Wenzel died 1793 (birth date unknown c. 1740): stoichiometry; concentration determines the speed of chemical reactions.

February 28

 - Chemistry Knowledge History


Edward Goodrich Acheson received US patent number 492,767 for production of artificial silicon carbide ("Carborundum"), 1893.

Steven Chu: laser cooling and trapping of atoms; US Secretary of Energy; Nobel (physics), 1997.
Edmond Fremy born 1814: plumbates, stannates, and ferrates; preparation of anhydrous hydrogen fluoride; coloring of flowers and saponification of fats

Philip Showalter Hench born 1896: hormones of the adrenal cortex; Nobel Prize (Medicine), 1950

Linus Carl Pauling born 1901: molecular structure, bonding (hybrid orbitals), electronegativity, and resonance (The Nature of the Chemical Bond); Nobel Prize, 1954; Nobel Peace Prize, 1962
February 29

Heike Kamerlingh Onnes announced solidification of helium, 1908.

National Science Day of India


Chemistry History
http://web.lemoyne.edu/~giunta/February.html

JEE - Study Guide - 4. Classification of Elements and Periodicity in Properties

Text Book of Dr. S.P. Jauhar CBSE Class XI

Sections of the Chapter

4.1 Development of the Periodic Table
4.2 Atomic Number of Modern Periodic Law
4.3 Electronic Configurations of the Elements in the Periodic Table
4.4 The Long form of Periodic Table
4.5 Division of Elements into s, p, d and f-Blocks
4.6 Periodic Properties
4.7 Atomic Radii
4.8 Ionic Radii
4.9 Ionization Enthalpy
4.10 Electron Gain Enthalpy
4.11 Valency


Conceptual Questions with Answers: 20

Revision Exercises
Very Short Answer questions 20
Short Answer Questions 40
Long Answer Questions 10

Competition File
Objective Questions: 50
Fill in the blanks: 11
True or False: 11


Study Plan

Day 1

4.1 Development of the Periodic Table
4.2 Atomic Number of Modern Periodic Law
4.3 Electronic Configurations of the Elements in the Periodic Table


Day 2

4.4 The Long form of Periodic Table
4.5 Division of Elements into s, p, d and f-Blocks

Ex. 4.1, 4.2, 4.3

Day 3

Practice Problems 4.1 to 4.8

Day 4

4.6 Periodic Properties
4.7 Atomic Radii
4.8 Ionic Radii

Ex. 4.5 to 4.7

Day 5

Practice Problems 4.9 to 4.13

Day 6

4.9 Ionization Enthalpy

Ex. 4.10, 4.11

Day 7

Practice Problems 4.14 to 4.16

4.10 Electron Gain Enthalpy

Day 8

Ex. 4.12 to 4.15
Practice Problems 4.17 to 4.20

Day 9

4.11 Valency
Chapter Round up

Day 10

Conceptual Questions with Answers: 20


Day 11

Very Short Answer questions 20


Day 12

Short Answer Questions 1 to 20

Day 13

Short Answer Questions 21 to 40

Day 14

Objective Questions: 1 to 25

Day 15

Objective Questions: 26 to 50

Revision Period

Day 16

Fill in the blanks: 11


Day 17

True or False: 11


Day 18

Long Answer Questions 1 to 3

Day 19

Long Answer Questions 4 to 6

Day 20

Long Answer Questions 7 to 10

Day 21 to Day 30

Revision of the chapter
Revision points of the chapter
http://iit-jee-chemistry.blogspot.in/2008/01/iit-jee-ch-4-periodicity-of-properties.html

Extra problems from other books like R.C. Mukherjee.
Use all available time productively to improve your understanding, ability to solve problems and recollection of principles


Play List

______________

______________
ExamFearVideos


5 Video Playlist - Rao IIT Academy
______________

______________

Updated  8 Feb 2016, 11 March 2009

Wednesday, February 3, 2016

6. Chemical Kinetics - JEE Main - CBSE XII - Core Revision Points

Importance of  Core Revision Points: Core Revision Points are important because if you remember them strongly, many more points related to them will come out of your memory and help you to answer question and problems. Read them many times and make sure you remember them very strongly.


Sections in the Chapter Jauhar

6.1 Rate of a chemical reaction
6.2 Experimental measurement of reaction rate
6.3 Factors which influence rates of chemical reactions
6.4 Dependence of reaction rates on concentration
6.5 Order of a reaction
6.6 Integrated rate expansion
6.7 Experimental determination of order of a reaction
6.8 Half life period of a reaction
6.9 Collision theory: Energy and orientation barriers to reactions
6.10 Dependence of reaction rates on temperature
6.11 Concept of activation energy and activated complex theory
6.12 Arrhenius equation and calculation of activation energy
6.13 Effect of radiations on reaction rates: photochemical reactions
6.14 Mechanism of a reaction
6.15 Fast reactions

Revision of the Chapter Video - Hindi
___________________

___________________

SardanaTutorials

Revision Points


The topic "Chemical kinetics" consists of reaction rate and reaction mechanism.

The branch of chemistry which deals with the rates of chemical reactions and the mechanism by which they occur, is called chemical kinetics.

Reaction rate is the speed with which a reaction takes place. This shows the rate or speed at which the reactants are consumed and products are formed.

Reaction mechanism is the path by which a reaction takes place.


6.1 Rate of a chemical reaction


Reaction rate is the speed with which a reaction takes place. This shows the rate or speed at which the reactants are consumed and products are formed.

Reaction mechanism is the path by which a reaction takes place.


Rate of reaction

The rate of reaction is a quantity that tells how the concentration of reactants or product changes with time.

So this can be expressed as Δ concentration/Δ time. That is change in concenation divided by time taken for the change.

Molar concentration i.e., moles per liter (M), is used in these equations.

The brackets, [ ] are always used to to indicate molar concentrations.


6.2 Experimental measurement of reaction rate


6.3 Factors which influence rates of chemical reactions


Temperature

As temperature increases, the average kinetic energy increases. So there are more molecules with activation energy and hence reaction rate increases.

As a general approximation, the rate roughly doubles for each 10°C rise in temperature.


6.4 Dependence of reaction rates on concentration


Law of Mass Action

In 1867, Cato Guldberg, and Peter Waage, proposed this law. According to this law, for the rate determining step in a reaction, the rate of reaction is proportional to the product of the concentrations of the reactants, each raised to the power of its coefficient in the balanced equation.

For the reaction aA + bB → cC (when it is a rate determining step)

Rate of reaction is proportional to [A]^a[B]^b

The above proportionality can be written as an equation, by putting in a proportionality constant k.

Rate = k *[A]^a[B]^b

K is called the specific rate constant

Rate law

The rate for a reaction is a mathematical expression that relates the rate of reaction to the concentrations of the reactants.

For the reaction aA + bB → products

The rate law is expressed as, rate of reaction is proportional to [A]^x[B]^y.
x and y are determined experimentally. These values can be whole or fractional numbers or zero.

Rate = k[A]^x[B]^y

k = the rate constant.
[A] and [B] are molar concentrations of reactants mol/litre

Units of rate: Rate is the change in concentration with time.

If the concentrations are expressed in moles/litre and time in seconds, then the units for rate of reaction are mol litre-1 s-1 or mol L-1s-1

Units of rate constant

Units of rate constant are different for different orders of reaction.

For zero order reactions units of rate constant are mol L-1s-1

For first order reactions units of rate constant are s-1

For second order reactions units of rate constant are L mol-1s-1

Basically units of rate constant are changing to give the rate of reaction in required units mol L-1s-1 (change in concentration with time).

In case of gases, the concentrations are expressed in terms of pressure in the units of atmosphere. Therefore the rate of reaction has the units of atm per second.


Integrated Rate Expressions

For zero order reactions

k0 = {[A]0 - [A]}/t

Where k0 = rate constant in the case of zero order reactions
[A]0 = Initial concentration of reactant A

[A] = concentration of reactant A at time t.
t = time

This can be alternatively expressed.

a = Initial concentration of reactant A (in moles per litre)
x = moles reactants that changed into products in time t
a-x = concentration of reactant A after time t

k0 = x/t

Where k0 = rate constant in the case of zero order reactions
x = moles reactants that changed into products in time t

For first order reactions

k1 = (2.303/t)log{[A]0/[A]}

Where k1 = rate constant for first order equations

Alternative expression



a = Initial concentration of reactant A (in moles per litre)
x = moles reactants that changed into products in time t
a-x = concentration of reactant A after time t

k1 = (2.303/t)log{a/(a-x)}

6.5 Order of a reaction

Order of a reaction

The sum of the powers to which the concentration terms are raised in the rate law expression.

For the expression Rate = k[A]^x[B]^y, the order of the reaction is x+y. The order of the reaction is represented by n.

When n = 1, the reaction said to be first order reaction.
n = 2 second order reaction etc.

There are number of reactions where rate of reaction is independent of concentration of reactants. The order of reaction is zero.





6.6 Integrated rate expansion
6.7 Experimental determination of order of a reaction
6.8 Half life period of a reaction
6.9 Collision theory: Energy and orientation barriers to reactions
6.10 Dependence of reaction rates on temperature
6.11 Concept of activation energy and activated complex theory

6.12 Arrhenius equation and calculation of activation energy


Reaction Rate Depends on Temperature

Temperature has influence on reaction rates. In general, an increase in temperature increases the rate of almost all reactions.

A general approximate rule is that the rate of a reaction becomes almost double for every 10° rise in temperature.

Activation Energy

For many reactions some extra energy is to be supplied to the reactants to initiate the reaction. This excess energy is required to bring the energy of reactants to the energy that is required to start the reaction. The energy of the reactants at which the reaction starts is called threshold energy.

Activation energy is the extra energy supplied to initiate the reaction. Thus activation energy is equal to the difference between the threshold energy and the average kinetic energy of the reacting molecules at the the given temperature (Note as activation energy is being given the temperature of the reactants increases)

Arrhenius Equation

Arrhenius proposed a quantitative relationship between rate constant and temperature

k = Ae(–Ea/RT)

where k = rate constant
A is a constant known as frequency factor. In a JEE problem it was termed as preexponential factor
–Ea is the activation energy
Both A and –Ea0 are characteristic of the equation
T is the absolute temperature and R is the gas constant

In log form the equation becomes

log k = log A - (Ea)/2.303 RT

As the activation energy –Ea0 increases, the value of k decreases and therefore, the reaction rate decreases.

Find the value of –Ea0

If log k is plotted against 1/T (both found through experiments), the intercept of the line will be equal to - (Ea)/2.303 R. Hence from the slope found from the graph - (Ea) can be found out as -2.303 R multiplied by slope.

Second Method

Measure rate constant at two temperatures k1 and k2 at T1 and T2

log (k2/k1) = (Ea/2.303 R)[ (1/T1) - (1/T2)]

JEE 2009 problem


For a first order reaction A→P, the temperature (T) dependent rate constant(k) was found to follow the equation logk = – (2000)(1/T) + 6.0
The pre-exponential factor A and the activation energy Ea, respectively, are -

Answer:
1.0 × 1066 s-1 and 38.3 kJ mol-1



6.13 Effect of radiations on reaction rates: photochemical reactions
6.14 Mechanism of a reaction
6.15 Fast reactions

Chemical Kinetics - 28 Videos Playlist - Examfearvideos
___________________

___________________


Updated 3 Feb 2016, 22 May 2015

5. Electrochemistry - JEE Main - CBSE Class XII - Core Revision Points

Importance of  Core Revision Points: Core Revision Points are important because if you remember them strongly, many more points related to them will come out of your memory and help you to answer question and problems. Read them many times and make sure you remember them very strongly.


Sections in the Chapter


5.1 Electrochemical changes: electrolytic and galvanic cells
5.2 Electrolysis and laws of electrolysis
5.3 Metallic and electrolytic conductance
5.4 Electrolytic conduction
5.5 Factors for the variation of molar conductance
5.6 Kohlrausch’s law
5.7 Electrochemical cell or galvanic cell
5.8 Representation of an electrochemical cell
5.9 Electrode potential and E.M.F. of a galvanic cell
5.10 Standard Electrode Potential
5.11 Electrochemical series
5.12 Differences between Galvanic cell and electrolytic cell
5.13 Dependence of electrode and cell potentials on concentration: Nernst Equations
5.14 Equilibrium constant form Nernst Equation
5.15 Electrochemical cell and free energy
5.16 Some commercial cells
5.17 Electrode potential electrolysis and criteria for product formation
5.18 Corrosion
5.19 Commercial production of chemicals
5.20 Manufacture of some important metals an chemical compounds



Sections in the Chapter


5.1 Electrochemical changes: electrolytic and galvanic cells

5.2 Electrolysis and laws of electrolysis


Faraday's laws of electrolysis:
---------------------------------------
Quantitative Relationships in Electrolytic Cells

Determining the amount of electrical energy necessary for accumulating a given amount material from the electrolytic cell.


First law: It states that the amount of any substance that is liberated at an electrode during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte.

W α Q (w = weight of substance deposited and Q is charge = ampere * time)

Second law: It states tht when the same quantity of electricity is passed through different electrolytes amount of different substances liberated or deposited at the different electrodes are directly proportional to the chemical equivalents9i.e., equivalent weight) of substances.

One faraday (F) is the amount of electrical energy required for flow of 1 mole of electrons.

To three significant digits, 1 faraday equals 96,500 coulombs(coul).

Current flow is measured in amperes (A)which is coulombs/seconds or coul/s,

5.3 Metallic and electrolytic conductance

Electrolytic conductance, specific, equivalent and molar conductance,



Electrolytic conductance


The flow of electric current through an electrolytic solution is known as electrolytic conduction.

Electrolytic conduction also follows Ohm's law.

V = I/R

R = ρ* l/a

ρ is called specific resistance.
The reciprocal of specific resistance is termed specific conductance. It may be defined as the conductance of a solution of 1 cm length and having 1 sq.cm as the area of cross section.

Specific conductance is the conductance of one centimetre cube of a solution of an electrolyte. It is denoted by k (kappa)

κ = 1/ρ

The equivalent conductivity of an electrolyte may be defined as the conductance of a volume of solution containing one equivalent mass of a dissolved substance when placed between two parallel electrodes which are at a unit distance apart, and large enough to contain between them the whole solution.

The molar conductivity of a solution gives the conducting power of ions produced by one molar mass of an electrolyte at any particular concentration.

It is denoted by Λm (Lambda).

Λm = κ/M

where M is the molar concentration





5.4 Electrolytic conduction
5.5 Factors for the variation of molar conductance

5.6 Kohlrausch’s law


Kohlrausch's Law on the independence of migrating ions: The molar conductivity of an electrolyte equals the sum of the molar conductivities of the cations and the anions; n = number of anions or cations.

Λ = v+Λ+ + vˉΛˉ

According to this law, the molar conductance of infinite dilution for a given salt can be expressed as the sum of the contributions from each ion of the electrolyte. If molar conductivity of the cation is denoted by Λˉ and anion by Λ+,and vˉ and v+ are number of cations and anions respectively, total molar conductance will be given by Λ.

Revision

1. Calculation of molar conductance at infinite dilution for weak electrolytes
2. Calculation of degree of dissociation of weak electrolytes

5.7 Electrochemical cell or galvanic cell




5.8 Representation of an electrochemical cell

5.9 Electrode potential and E.M.F. of a galvanic cell


The difference between the electrode potentials of the two electrodes constituting an electrochemical cell is known as electromotive force or cell potential of a cell.


5.10 Standard Electrode Potential

5.11 Electrochemical series


The electrochemical series is built up by arranging various redox equilibria in order of their standard electrode potentials (redox potentials). The most negative E° values are placed at the top of the electrochemical series, and the most positive at the bottom.



The electrochemical series

equilibrium E° (volts)
Li-3.03
K -2.92
Ca -2.87
Na -2.71
Mg -2.37
Al -1.66
Zn -0.76
Fe-0.44
Pb -0.13
H 0
Cu +0.34
Ag+0.80
Au +1.50

Remember that in terms of electrons:

OIL RIG

Oxidation is loss Reduction is gain


Reducing agents and oxidising agents

reducing agent reduces something else. That must mean that it gives electrons to it.

Magnesium is good at giving away electrons to form its ions. Magnesium must be a good reducing agent.

An oxidising agent oxidises something else. That must mean that it takes electrons from it.

Copper doesn't form its ions very readily, and its ions easily pick up electrons from somewhere to revert to metallic copper. Copper(II) ions must be good oxidising agents.

5.12 Differences between Galvanic cell and electrolytic cell


5.13 Dependence of electrode and cell potentials on concentration: Nernst Equations



Nernst Equation: The cell potential of a half cell (as well as that of a complete cell) depends upon the concentrations of involved ions, pressure of the gaseous species (if involved) and the temperature. The relation connecting them is given by the Nernst equation.

It is expressed as

E = E° - (RT/nF)ln Q°

Q° = Product of concentration (or pressure) of products each raised to the corresponding stochiometric number/Product of concentration (or pressure) of reactants each raised to the corresponding stochiometric number

n = number of electrons involved in the hall cell reaction

5.14 Equilibrium constant form Nernst Equation
5.15 Electrochemical cell and free energy
5.16 Some commercial cells
5.17 Electrode potential electrolysis and criteria for product formation
5.18 Corrosion
5.19 Commercial production of chemicals
5.20 Manufacture of some important metals an chemical compounds


ElectroChemistry - 35 Video Playlist

_____________________

_____________________
ExamFearVideos

Updated 3 Feb 2016,  22 May 2015