2. Writing compound name of 2-Bromo-5-hydroxybenzonitrile given the pictorial view of the molecule.
(Cyanide group has higher priority than phenol. Hence correct IUPAC name is
2-Bromo-5-hydroxybenzonitrile)
3. Atomic mass of an element having isotopes
Given that the abundances of isotopes 54Fe, 56Fe and 57Fe are 5%, 90% and 5 %, respectively, the atomic mass of Fe is -
(A) 55.85 (B) 55.95
(C) 55.75 (D) 56.05
[Ans. B]
4. Polymers
Among cellulose, poly(vinyl chloride), nylon and natural rubber, the polymer in which the intermolecular
force of attraction is weakest is -
(A) Nylon (B) Poly(vinyl chloride)
(C) Cellulose (D) Natural Rubber
[Ans. D]
Sol. Natural rubber is an example of elastomers, which has weakest intermolecular forces (dispersion forces).
5. Henry's Law
The solubility of a gas is related to its pressure by Henry's law.
The mass of a gas dissolved per unit volume of the solvent at a given temperature is proportional to the pressure of the gas in equilibrium with the solution.
m = Kp
m = mass of the gas dissolved in a unit volume of the solvent.
p = is the pressure of the gas in equilibrium with the solution
K = proportionality constant
Alternative statement
The pressure of a gas over a solution in which the gas is dissolved is proportional to the mole fraction of the gas dissolved in the solution.
p = Kx
p = partial vapour pressure
x = mole fraction of the gas in the solvent
K = Henry's law constant
Problem
The Henry's law constant for the solubility of N2 gas in water at 298 K is 1.0 × 105
atm. The mole fraction of N2 in air is 0.8. The number of moles of N2 from air dissolved in 10 moles of water at 298 K and 5 atm
pressure is -
Answer: 4.0 × 10-4
6. Acidity order of aromatic carboxylic acids and phenol
Benzoic acid (–COOH) is more acidic than phenol. Electron withdrawing group increase acidic nature &
electron donating group decrease acidity.
7. Among the electrolytes Na2SO4, CaCl2, Al2(SO4)3 and NH4Cl, the most effective coagulating agent for
Sb2S3 sol is -
Sb2S3 is negatively charged sols. Because of the formation higher positive charge ions coagulating power
of Al2(SO4)3 is the highest
8. Reactions of Phosphorous
The reaction of P4 with X leads selectively to P4O6. The X is -
(A) Dry O2 (B) A mixture of O2 and N2
(C) Moist O2 (D) O2 in the presence of aqueous NaOH
Answer B
P4 is converted to P4O6 in the presence of limited supply of oxygen.
9. Reactions of Sodium
The compound(s) formed upon combustion of sodium metal in excess air is(are) -
10. Defects of Solids
The correct statement(s) regarding defects in solids is(are) -
(A) Frenkel defect is usually favoured by a very small difference in the size of cation and anion
(B) Frenkel defect is a dislocation defect
(C) Trapping of an electron in the lattice leads to the formation of F-center
(D) Schottky defects have no effect on the physical properties of solids
Answers: B,C
11. Geometrical isomerism of organometallic compounds
12. Stereoisomers
The correct statement(s) about the compound H3C(HO)HC–CH=CH–CH(OH)CH3 (X) is (are)
(A) The total number of stereoisomers possible for X is 6
(B) The total number of diastereomers possible for X is 3
(C) If the stereochemistry about the double bond in X is trans, the number of enantiomers possible for X is 4
(D) If the stereochemistry about the double bond in X is cis, the number of enantiomers possible for X is 2
Answer: A,D
13. Anilines
p-Amino-N, N-dimethylaniline is added to a strongly acidic solution of X. The resulting solution is treated
with a few drops of aqueous solution of Y to yield blue coloration due to the formation of methylene blue.
Treatment of the aqueous solution of Y with the reagent potassium hexacyanoferrate (II) leads to the
formation of an intense blue precipitate. The precipitate dissolves on excess addition of the reagent.
Similarly, treatment of the solution of Y with the solution of potassium hexacyanoferrate (III) leads to a
brown coloration due to the formation of Z.
Questions: Find compound X,Y and Z
14. Carbonyl Compounds
A carbonyl compound P, which gives positive iodoform test, undergoes reaction with MeMgBr followed
by dehydration to give an olefin Q. Ozonolysis fo Q leads to a dicarbonyl compound R, Which undergoes
intramolecular aldol reaction to give predominantly S.
Questions asked on Structure of P,Q,R and S
15. Attaching these properties to elements in matching
(p) Paramagnetic
(q) Undergoes oxidation
(r) Undergoes reduction
(s) Bond order ≥ 2
(t) Mixing of 's' and 'p' orbitals
16. Matching of characteristic reactions with compounds
(p) Reduction with H2/Pd-C
(q) Reduction with SnCl2/HCl
(r) Development of foul smell on treatment with chloroform and
alcoholic KOH
(s) Reduction with disobutylaluminium hydride (DIBAL-H)
(t) Alkaline hydrolysis
Compounds
(A) CH3CH2CH2CN, (B) CH3CH2OCOCH3, (C) CH3 – CH = CH – CH2OH, (D) CH3CH2CH2CH2NH2
For question paper
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