Monday, February 4, 2008

IIT JEE Revision - Chemistry Ch 1. THE BASIC CONCEPTS - Core Points

JEE Syllabus

General topics:

The concept of atoms and molecules;
Dalton's atomic theory;
Mole concept;
Chemical formulae;
Balanced chemical equations;
Calculations (based on mole concept) involving common oxidation-reduction, neutralisation, and displacement reactions;
Concentration in terms of mole fraction, molarity, molality and normality.

Stochiometric coefficients or numbers: The numbers which appear before the chemical symbols in a chemical equation.

Chemical equation gives information about moles of various reactants and products. Hence molar masses involved in the reaction and molar masses of products.

Mass percentage of substance in a system

Mole fraction of a substance in a system

Molarity = Amount of a substance (in mol)/Volume of solution expressed in dm^3
It is applicable to solutions only.

The unit of molarity is mol dm^-3. It is commonly abbreviated by the symbol M and is spelled as molar.

Molality = Amount of a a substance (in mol)/Mass of solvent expressed in kg
It is also applicable to solutions only


"One equivalent of a substance in a reaction is defined as the amount of substance which reacts or liberates 1 mol of electrons (or H^+ or OH^- ions).

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