Jamb Chemistry 1985 Past Questions and Answers

Question 26:

• JAMB 1985

An aqueous solution of an inorganic salt gave white precipitate (i) soluble in excess aqueous NaOH (ii) insoluble in excess aqueous NH₃ (iii) with dilute HCl. The cation present in the inorganic salt is?

A. Na₄⁺
B. Ca⁺⁺
C. Zn⁺⁺
D. Al⁺⁺⁺
E. Pb₊₊

Question 27:

• JAMB 1985

Which of the following roles does sodium chloride play in soap preparation? It

A. Reacts with glycerol
B. Purifies the soap
C. Accelerates the decomposition of the fat or oil
D. Separates the soap from the glycerol
E. Converts the fatty acid to its sodium salt

Question 28:

• JAMB 1985

The function of sulphur during vulcanization rubber is to?

A. Act as catalyst for the polymerization of rubber molecules
B. Convert rubber from thermosetting to thermo plastics polymer
C. From chains which bind rubber molecules together
D. Break down rubber polyer
E. Shorten the chain length of rubber polyer

Question 29:

• JAMB 1985

Figure 1 above shows part of the periodic Table which of the elements belongs to the p-block?

A. S, T and U
B. V, W and X
C. S and T only
D. P, Q and R
E. V, W, X and S

Question 30:

• JAMB 1985

The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. At room temperature (300 K)

A. Y is twice as soluble as X
B. X is twice as soluble as Y
C. X and Y are soluble to the same extent
D. X is three times as soluble as Y
E. Y is three times as soluble as X