Tests for oxidizing and reducing agents - Jamb Chemistry Past Questions and Answers

Question 1:

• JAMB 2019

Consider the following equation H₂O + 2Fe²⁺ + Cl₂ 2Fe³⁺ + 2Cl^- + H₂O. The only ion which behaves as an oxidising agent is

A. Fe²⁺
B. Cl₂
C. Fe³⁺
D. Cl^-
E. H₂O

Question 2:

• JAMB 2019

If hydrogen sulphide gas is passed into a solution of a pure iron chloride, a yellow deposit appears. If the deposit is filtered, a pale green solution is left behind. The pale green solution is

A. Dilute sulphuric acid
B. Dilute hydrochloric acid
C. Unreacted hydrogen sulphide in water
D. Iron (III) chloride
E. Iron (II) chloride

Question 3:

• JAMB 2019

X is a substance which liberates CO₂ on treatment with concentrated H₂SO₄. A warm solution of X can decolorize acidified KMnO₄. X is

A. HCOOH
B. NaH CO₃
C. FeCO₃
D. H₂C₂O₄

Question 4:

• JAMB 1978

If hydrogen sulphide gas is passed into a solution of a pure iron chloride, a yellow deposit appears. If the deposit is filtered, a pale green solution is left behind. The pale green solution is

A. Dilute sulphuric acid
B. Dilute hydrochloric acid
C. Unreacted hydrogen sulphide in water
D. Iron (III) chloride
E. Iron (II) chloride

Question 5:

• JAMB 1979

The reaction of zinc with copper (ll) ions in aqueous solution can be represented as follows: Cu ²⁺(aq) +Zn (s) → Cu(s) + Zn ²⁺(aq).Which of the following is the most complete description of this reaction?

A. Cpper (ll) ions are being reduced
B. Zinc is being oxidized.
C. Copper (ll) ions and zinc are being reduced
D. Copper (ll) ions and zinc are being oxidized
E. Copper(ll) ions are being reduced and zinc oxidized