STOICHIOMETRY, ITS ASSUMPTIONS AND CALCULATIONS - FIRST YEAR CHEMISTRY

Stoichiometry, Its Assumptions and Calculations

Stoichiometry

     The branch of chemistry which deals with the study of quantitative relationship between reactants and products in a balanced chemical equation is called stoichiometry. 

Stoichiometric Amounts

     The amounts of the reactants or the products as given by the balanced chemical equation are called stoichiometric amounts. 

2H2     +     O2    →     2H2O

2 mole       1 mole         2 moles

4 g            32 g             36 g

Assumptions

     When stoichiometric calculations are performed, we have to assume the following conditions.

(i) All the reactants are completely converted into products.

(ii) No side reaction occurs.

     During stoichiometric calculations, law of conservation of mass and law of definite proportions are obeyed. 

Calculations

(i) Mass-mass Relationship: If we are given mass of one substance, we can calculate the mass of the other substance involved in the chemical reaction.

(ii) Mass-mole Relationship: If we are given the mass of one substance, we can calculate the moles of the other substance and vice versa.

(iii) Mass-volume Relationship: If we are given mass of one substance, we can calculate the volume of the other substance and vice versa. 

(iv) Similarly, mole-mole calculations can also be performed. 

Notes Prepared By: Prof. Shahbaz Asghar