Waec Chemistry 1997 Past Questions and Answers

Question 21:

• WAEC 1997

If the value of ∆H for a reaction is negative, it means that the reaction is

A. Slow
B. Exothermic
C. Spontaneous
D. Irreversible
E. Not feasible

Question 22:

• WAEC 1997

How much heat will be liberated if 8g of hydrogen burns in excess oxygen according to the following equation? 2H₂ + O₂→ 2H₂O,∆H = -571.7KJ (H = 1)

A. 1.42.9KJ
B. 571.7KJ
C. 1143.4KJ
D. 285.9KJ
E. 2286.8KJ

Question 23:

• WAEC 1997

The position of equilibrium in a reversible reaction is affected by

A. Particle size of the reactants
B. Change in concentration of the reactants
C. Change in size of the reaction vessel
D. Vigorous stirring of the reaction mixture
E. Presence of a catalyst

Question 24:

• WAEC 1997

Separation of mixture of solids by physical methods can be based on differences in the following except

A. Melting point
B. Solubility
C. Particle size
D. Molar mass
E. Magnetic property

Question 25:

• WAEC 1997

Ethene undergoes mainly addition reactions because it is

A. A gas
B. A hydrocarbon
C. Unsaturated
D. Easily polymerized
E. A covalent compound