Jamb Chemistry Past Questions and Answers

Question 156:

• 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 157:

• 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 158:

• 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 159:

• 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

Question 160:

• JAMB 1980

In an attempt to remove sugar from a breaker containing a quantity of sand and sugar, 2 M ammonium chloride solution was accidentally added instead of water. Which of the following method could be used to remove the ammonium chloride from the mixture?

A. Fractional distillation
B. Crystallization
C. Filtration followed by evaporation
D. Evaporation followed by sublimation
E. Filtration followed by sublimation