Energy changes - Jamb Chemistry Past Questions and Answers

Question 61:

• 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 62:

• 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 63:

• JAMB 2009

C_(s) + H₂O_(g) → H_2(g) + CO_2(g)
ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is

A. Not feasible
B. At equilibrium
C. Feasible
D. Exothermic

Question 64:

• JAMB 2009

Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth - to - mouth to each other at room temperature. The entropy in the mixture of gases is likely to

A. Remain unchange
B. Increase
C. Decrease
D. Change

Question 65:

• JAMB 2009

One of the products of the thermal decomposition of sodium trioxonitrate (V) is

A. Sodium
B. Nitrogen
C. Sodium dioxonitrate (III)
D. Sodium oxide