Oxidation and reduction - Jamb Chemistry Past Questions and Answers

Question 26:

• JAMB 1984

An aqueous solution of a metal salt, M, gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia. Therefore cartion in M is

A. Zn ⁺⁺
B. Ca⁺⁺
C. Ai⁺⁺⁺
D. Pb⁺⁺
E. Cu⁺⁺

Question 27:

• JAMB 1985

2MnO^-₄ + 10Cl^- + 16H⁺ → 2Mn²⁺ + 5Cl₂ + 8H₂O. Which of the substances serves as an oxidizing agent?

A. Mn²⁺
B. Cl^-
C. H₂O
D. MnO^-₄
E. Cl₂

Question 28:

• JAMB 1985

Which of the following metals will displace iron from a solution of iron(ll)tetraoxosulphate(lV)?

A. Copper
B. Mercury
C. Silver
D. Zinc
E. Gold

Question 29:

• JAMB 1985

The oxidation of

A. 2-butanone
B. 2-butanal
C. Butane
D. Butanoic acid
E. 3-butanal

Question 30:

• JAMB 1985

Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because

A. Zinx is not rendered passive by acid
B. Hydrogen produced is oxidized to water
C. Oxides of nitrogen are produced
D. All nitrates are soluble in water
E. Trioxonitrate(v)acid is a strong acid