Jamb Chemistry 1980 Past Questions and Answers

Question 41:

• JAMB 1980

Copper sulphate solution was electrolysed using the apparatus show above. Which of the following changes are observed?

A. The bulb lights and copper is deposited at both electrodes
B. The bulb lights and copper is deposited at the anode and disappears from the cathode
C. The bulb lights and copper is deposited at the cathode and oxygen liberated at the anode
D. The bulb lights and copper is deposited at the cathode and disappears from the anode
E. The bulb lights but no additional changes are observed

Question 42:

• 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 43:

• 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 44:

• 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 45:

• 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