Chemical equilibrium - Jamb Chemistry Past Questions and Answers

Question 11:

• JAMB 1992

Which of the following equilibria shows little or no net reaction when the volume of the system is decreased?

A. H_2(g) + I_2(g) ≈ 2HI_(g)
B. 2NO₂^(g) ≈ N₂O_4(g)O_4(g)N₂O_4(g)
C. PCI_5(g) ≈ PCI_3(g) + CI_2(g)
D. ZnO_(s) + CO_2(g) ≈ ZnCO_3(g)

Question 12:

• JAMB 1992

For a general equation of the nature xP + yQ ≈ mR + nS, the expression for the equilibrium constant is?

A. K (p)^x (Q)^y
B. (p)^x (Q)^y / (R)^m (S)ⁿ
C. (R)^m (S)ⁿ / (p)^x (Q)^y
D. M(R) n (S) / x(P) y (Q)

Question 13:

• JAMB 1993

10g of a solid is in equilibrium with its own vapour.
When 1 g of a small amount of solid is added, the vapour pressure?

A. Remains the same
B. Drops
C. Increases by 1%
D. Increases by 99%

Question 14:

• JAMB 1994

Which of the following is TRUE of Le Chatelier's Principle for an exothermic reaction?

A. Increase in temperature will cause an increase in the equilibrium constant
B. Increase in temperature will cause a decrease in the equilibrium constant
C. Addition of a catalyst will cause an increase in the equilibrium constant
D. Addition of a catalyst will cause a decrease in the equilibrium constant

Question 15:

• JAMB 1995

If an equilibrium reaction has ∆H < O, the reaction will proceed favorably in the forward reaction at?

A. Low temperatures
B. High temperatures
C. All temperatures
D. All pressures