Jamb Chemistry 2010 Past Questions and Answers

Question 26:

• JAMB 2010

In which of the following is the entropy change positive?

A. Thermal dissociation of ammonium chloride
B. Reaction between an acid and a base
C. Addition of concentrated acid to water
D. Dissolution of sodium metal in water

Question 27:

• JAMB 2010

If a reaction is exothermic and there is a great disorder, it means that

A. The reaction is static
B. The reaction is in a state of equilibrium
C. There will be a large increase in free energy
D. There will be a large decrease in free energy

Question 28:

• JAMB 2010

In the preparation of oxygen by heating KClO₃ in the presence of MnO₂, only moderate heat is needed because the catalyst acts by

A. Lowering the pressure of the reaction
B. Increasing the surface area of the reactant
C. Increase the rate of the reaction
D. Lowering the energy barrier of the reaction

Question 29:

• JAMB 2010

The graph above demonstrate the effect of

A. Surface area on the rate of reaction
B. Catalyst on the rate of reaction
C. Pressure on the rate reaction
D. Concentration on the rate of reaction

Question 30:

• JAMB 2010

2H_2(g) + O_2(g) → 2H₂O_(g) ΔH = -ve
what happens to the equilibrium constant of the reaction above if the temperature is increased?

A. It is unaffected
B. It becomes zero
C. It decrease
D. It increase