Waec Chemistry 2002 Past Questions and Answers

Question 31:

• WAEC 2002

What will happen if more heat is applied to the following system at equilibrium? X_2(g) + 3Y _2(g) ⇌ 2XY_3(g); ∆H = xKJmol^-1

A. The yield of XY ₃ will decompose
B. More of XY₃ will decompose
C. More of X₂ will react
D. The forward reaction will go to completion

Question 32:

• WAEC 2002

What is the expression for the equilibrium constant (K_c) for the following reaction? N_2(g) + O_2(g) ⇌ 2NO_(g)

A. \(\frac{[NO^2]}{[N^2] + [O^2]}\)
B. \(\frac{[2NO]^2}{[N_2][O_2]}\)
C. \(\frac{[N_2] + [O_2]}{2[NO]^2}\)
D. \(\frac{[NO]^2}{[N_2][O^2]}\)

Question 33:

• WAEC 2002

Equal amounts of marble chips are reacted separately with 100cm³ of hydrochloric acid of different concentrations. If all the marble chips reacted; which of the following remained the same in each case?

A. Average rate of evoluton of gas
B. Total mass of gas evolved during the reaction
C. Time taken for the reaction to reach completion
D. Initial reaction rates

Question 34:

• WAEC 2002

CuSO₄5H₂O can be obtained from an aqueous solution of copper (ll) tetraoxosulphate (VI) by

A. Evaporation to dryness
B. Using chromatography
C. Precipitation
D. Crystallization

Question 35:

• WAEC 2002

Which of the following compounds will leave a metal residue when heated?

A. Cu(NO₃)₂
B. AgNO₃
C. K₂CO₃
D. CaCO₃