Waec Chemistry 1999 Past Questions and Answers

Question 26:

• WAEC 1999

If the solubility of KHCO₃ is 0.40 mole dm^{-3 at room temperature , calculate the mass of KHCO₃ in 100dm[sup]3} of the solution at this temperature. [KHCO₃ = 100hmol]
[/sup]

A. 4.0g
B. 10.0g
C. 40.0g
D. 100.0g

Question 27:

• WAEC 1999

The property of calcium chloride which makes it useful as a drying agent is that it is

A. Ionic
B. Deliquescent
C. A strong electrolyte
D. A normal salt

Question 28:

• WAEC 1999

Which of the following lowers the activation energy of a chemical reaction?

A. Freezing mixture
B. Reducing agent
C. Water
D. Catalyst

Question 29:

• WAEC 1999

Consider the reaction represented by the following equation: H_2(g) + 1_2(g) → 2HI_(g). The number of effective collisions of molecules of the reactants decreases as

A. The temperature is raised
B. The pressure increased
C. The volume of the system is increased
D. A catalysty is intoduced into the system

Question 30:

• WAEC 1999

What will be the effect of increase in pressure on the following system at equilibrium? 2NH_2(g) N_2(g) + 3H_2(g)

A. Activation energy will decrease
B. The forward reaction will be favoured
C. The concentration of ammonia will increase
D. The reaction will go to completion