Oxidation and reduction - Jamb Chemistry Past Questions and Answers

Question 61:

• JAMB 2000

(1/2)Zn²⁺_(aq) + e^- → (1/2) Zn_(s)
In the reaction above, calculate the quantity of electricity required to discharge zinc.
[F = 96 500 C mol^-1]

A. 0.965 * 10₄C
B. 4.820 * 10₄C
C. 9.650 * 10₄C
D. 48.200 * 10₄C

Question 62:

• JAMB 2001

In which of the following reactions does reduction takes place

A. Fe²⁺ - e^- → Fe³⁺
B. 2O^2- →O₂ + 4e^-
C. Cr – 2e^- → Cr²⁺
D. 2H⁺ + 2e^- → H₂

Question 63:

• JAMB 2001

P_(g) + Q_(g) ↔ 3R_(s) + S_(g) ΔH is negative
Which of the following will increase the yield of R?

A. Using a larger close vessel
B. Increasing the temperature
C. Removing some S
D. Adding a positive catalyst

Question 64:

• JAMB 2001

3Cu_(s) + 8HNO_3(aq) 3Cu(NO₃)_2(aq) + 4H₂O_(l) + 2NO_(g)
In the equation above, copper is

A. An electron acceptor
B. A base
C. An oxidizing agent
D. A reducing agent

Question 65:

• JAMB 2001

In which of the following reactions has the oxidation number of nitrogen increased?

A. 2NO_(g) + Br_2(l) → 2NOBr_(l)
B. 2NO_(g) + O_2(g) → 2NO_2(g)
C. FeSO_4(aq) + NO_(g) → Fe(NO)SO_4(s)
D. 2NO(g) + Cl_2(g) → 2NOCl(l)