Jamb Chemistry Past Questions and Answers

Question 201:

• JAMB 1980

The following arrangement of elements in order of decreasing number of outer electrons; One of the elements is wrongly placed. Which is it? ALUMINIUM, CHLORINE, SILICON, MAGNESIUM AND SODIUM.

A. Chlorine
B. Aluminium
C. Silicon
D. Magnesium
E. Sodium

Question 202:

• JAMB 1980

Which of the following tests would confirm-unequivocally that a solution X contain the sulphate ion if it gives with

A. Silver nitrates solution, a white precipates insoluble in dilute HNO₃
B. Barium chloride solution, a white precipitate insoluble in dilute H₂SO₄
C. Barium chloride solution, a white precipitate insoluble in dilute HCl
D. Barium chloride solution a white precipitate soluble in dilute ammonia
E. Barium chloride solution a white precipitate insoluble in dilute HCl

Question 203:

• JAMB 1980

When copper (ii) sulphate solution is treated with excess ammonium hydroxide, a precipitate is first formed, and then this dissolves to give a deep blue solution. This deep blue solution is a

A. Cu(OH)₂
B. CuSo₄.5H₂O
C. (NH₄)₂SO₄
D. Cu(NH₃)₄(OH)₂
E. CuSO₄.(NH₄)₂SO₄.2H₂O

Question 204:

• JAMB 1980

Which of the following derivatives of nitrogen affords an aqueous solution having a pH of less that 7?

A. N₂O
B. NO
C. NO₂
D. NaNO₃
E. NH₃

Question 205:

• JAMB 1980

Detergents are more advantageous than soaps in hard water districts because

A. On treatment with hard water they either form soluble calcium salts or do not react with calcium ion
B. On treatment with hard water they form soluble calcium salts
C. On treatment with hard water they form sodium salts
D. On treatment with hard water they are converted into soaps
E. On treatment with hard water they form more lather than soaps does