Jamb Chemistry 1979 Past Questions and Answers

Question 46:

• JAMB 1979

A piece of metal (M) is dissolved in nitric acid and the resulting solution is treated with a small quantity of sodium hydroxide to produce a white precipitate (B) which redissolves on the addition of excess alkali. The precipitate (B)when ignited in a crucible produces the oxide of the metal(m). The METAL M is

A. Zn
B. Cu
C. Al
D. Au
E. Ca

Question 47:

• JAMB 1979

Pick out the correct statement

A. Zin heated to redness reacts with steam to give oxygen and zinc oxide
B. Zinc heated to redness reacts with steam to give oxygen and hydrogen
C. Zinc does not react with hot or cold water
D. Zinc reacts with hot water to form zinc oxide and hydrogen
E. Zinc reacts very easily with cold water to give zinc oxide and hydrogen

Question 48:

• JAMB 1979

Consider the following exothermic reaction 2SO₂(g) + O₂(g) = 2SO₃ (g) . If the temperature of the reaction is reduced from 800_oC to 500_oC, and 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. O₂ gas becomes unreactive

Question 49:

• JAMB 1979

The IUPAC name for

A. 2-methylbut-3-ene
B. 2-methylbut-4-ene
C. 3-methylbut-2-ene
D. 3-methylbut-1-ene
E. 3-methylpent-1-ene