Chemistry Past Questions and Answers

What is the expression for the equilibrium constant (Kc) for the following reaction? N2(g) + O2(g) â‡Œ 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 2732:

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 2733:

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 2734:

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

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

Question 2735:

A visible change is observed when a strip of iron is placed in an aqueous solution of

A FeSO4
B ZnSO4
C CuSO4
D MgSO4