Oxidation and reduction - Jamb Chemistry Past Questions and Answers

Question 31:

• JAMB 1988

The ion that may be assumed to have negligible concentration in a sample of water that lathers readily with soap is?

A. Mg⁺
B. K⁺
C. CO₂^2-
D. HCO₃

Question 32:

• JAMB 1988

Which of the following acts both s a reducing and an oxidizing agent?

A. H₂
B. SO₂
C. H₂S
D. C

Question 33:

• JAMB 1988

A mixture of starch solution and potassium iodide was placed in a test tube. On adding dilute tetraoxosulphate (lV) acid and then K₂Cr₂O₇ solutions, a blue-black colour was produced. In this reaction, the?

A. Iodide is oxidized
B. Tetraoxosulphate (Vl) acid acts as an oxidizing agent
C. Starch has been oxidized
D. K₂Cr₂O₇ is oxidized

Question 34:

• JAMB 1988

A metallic ion X²⁺ with an inert gas structure contains 18 electrons. How many protons are there in this ion?

A. 20
B. 18
C. 16
D. 2

Question 35:

• JAMB 1988

What are the possible oxidation numbers of an element if its atomic number is 17?

A. -1 and 7
B. -1 and 6
C. -3 and 5
D. -2 and 6