Jamb Chemistry 2008 Past Questions and Answers

Question 26:

• JAMB 2008

If a given quantity of electricity liberates 0.65g of Zn²⁺, what amount of Hg²⁺ would be liberated by the same quantity of current?
[Zn = 65, Hg = 201]

A. 1.00g
B. 2.10g
C. 4.02g
D. 8.04g

Question 27:

• JAMB 2008

NH_3(g) + HCl_(s) → NH₄Cl_(s)
The entropy change in the system above is

A. Positive
B. Zero
C. Negative
D. Indeterminate

Question 28:

• JAMB 2008

Which of the following reaction is endothermic?

A. C_(s) + O_2(g) → CO_2(g)
B. CaO_(s) + H₂O_(l) → Ca(OH)_2(s)
C. C_(s) + H₂O_(g) → CO_(g) + H_2(g)
D. HCl_(aq) + NaOH_(aq) → NaCl_(aq) + H₂O_(l)

Question 29:

• JAMB 2008

A catalyst speeds up the rate of chemical reaction by

A. Taking part in the reaction
B. Increasing the activation energy of the reaction
C. Lowering the activation energy of the reaction
D. Increasing the heat content

Question 30:

• JAMB 2008

The rate of a reaction usually decrease in the concentration of reactants because

A. Kinetic energy decrease
B. Temperature increase
C. Speed increases
D. Reactants collision decrease