Jamb Chemistry 1999 Past Questions and Answers

Question 16:

• JAMB 1999

The correct order of increasing oxidation number of the transition metal ions for the compounds K₂Cr₂O₇, V₂O₅ and KMnO₄ is

A. V₂O₅ < K₂Cr₂O₇ < KMnO₄
B. K₂Cr₂O₇ < KMnO₄ < V₂O₅
C. KMnO₄ < K₂Cr₂O₇ < V₂O₅
D. KMnO₄ < V₂O₅ < K₂Cr₂O₇

Question 17:

• JAMB 1999

The set of pollutants that is most likely to be produced when petrol is accidentally spilled on plastic materials and ignited is

A. CO, CO² and SO²
B. CO, HCL and SO²
C. CO, CO² and HCL
D. SO², CO² and HCL

Question 18:

• JAMB 1999

What is observed when aqueous solutions of each of tetraoxosulphate (VI) acid, potassium trioxoiodate (V) and potassium iodide are mixed together?

A. A white precipitate is formed
B. A green precipitate is formed
C. The mixture remains colourless
D. The mixture turns reddish brown

Question 19:

• JAMB 1999

The solution with the lowest pH value is

A. 5 ml of (m/10) HCL
B. 10 ml of (m/10) HCL
C. 15 ml of (m/5) HCL
D. 20 ml of (m/8) HCL

Question 20:

• JAMB 1999

The solubility product of Cu(IO₃)₂ is 1.08 * 10^-7. Assuming that neither ions react appreciable with water to form H⁺ and OH^-, what is the solubility of this salt?

A. 2.7 * 10^-8 mol dm^-3
B. 9.0 * 10^-8 mol dm^-3
C. 3.0 * 10^-3 mol dm^-3
D. 9.0 * 10^-3 mol dm^-3