Jamb Chemistry 1978 Past Questions and Answers

Question 31:

• JAMB 1978

The most common type of chemical reaction which alkanes undergo is

A. Substitution
B. Addition
C. Condensation
D. Polymerisation
E. Double decomposition

Question 32:

• JAMB 1978

Consider the following exothermic reaction
2SO_2(g) + O_2(g) ↔ 2SO_3(g)
If the temperature of the reaction is reduced from 800°C to 500°C, an no other change takes place, then

A. The reaction rate increases
B. Concentration of SO₃ decreases
C. Concentration of SO₃ increases
D. SO₂ gas becomes unreactive
E. O₃ gas becomes unreactive

Question 33:

• JAMB 1978

If excess zinc is added to a bluish green solution of copper (II) sulphate, and the excess zinc filtered off after completion of reaction, a colourless solution is obtained because

A. Both zinc and copper are metals
B. The sulphate radical and the zinc ion are divalent
C. Zinc is more electropositive than copper
D. Both zinc and copper form depositive ions in solution
E. Zinc is a reducing agent

Question 34:

• JAMB 1978

Three solutions contain carbonate, sulphate and sulphide ions respectively. One test that will identify just ONE of them completely is by addition to each of them of

A. Barium chloride solution
B. Dilute hydrochloric acide
C. Lead nitrate solution
D. Calcium chloride solution
E. Sodium hydroxide solution

Question 35:

• JAMB 1978

Two gas cylinders contain ethylene (ethene) and acetylene respectively. One test which can be used to distinguish between them is by

A. Passing each gas through bromine water
B. Passing each gas through dilute potassium permanganate solution
C. Passing each gas through silver nitrate solution
D. Treating each gas catalytically with excess hydrogen gas