Acids, bases and salts - Jamb Chemistry Past Questions and Answers

Question 11:

• JAMB 1978

A solid X when heated gives off a brown gas. If X is soluble in excess sodium hydroxide solution but insoluble in excess ammonium hydroxide solution, then X is

A. Basic lead carbonate
B. Lead (II) nitrate
C. Sodium carbonate
D. Zinc nitrate
E. Sodium nitrate

Question 12:

• JAMB 1979

Which of the following contains two amphoteric oxides?

A. Sodium oxide, Zinc oxide , Magnesium oxide
B. Aluminium oxide, Calcium oxide, Zinc oxide
C. Potassium oxide, Lithium oxide, Carbon monoxide
D. Silver oxide, Lead oxide, Sodium oxide
E. Sulphur dioxide, Aluminium oxide, Carbon monoxide

Question 13:

• JAMB 1979

In the redox reaction 2Fe²⁺ + CI₂ → 2Fe ^{3 +} + 2Cl

A. Cl₂ is reduced because it has lost electrons
B. Cl₂ is reduced because its oxidation number has decreased
C. Cl₂ is reduced because its molecule is change to two ions
D. Fe²⁺ is reduced because it has lost electrons
E. Fe²⁺ is reduced because it has gained electrons

Question 14:

• JAMB 1979

An anhydride is

A. A compound wich has no water of crystallization
B. An oxide whose solution in water has a PH greater than 7
C. An oxide whose solution in water has a PH less than 7
D. An oxide that has hydrogen atoms
E. An amphoteric oxide

Question 15:

• JAMB 1979

The solution of a sample in a tube will be identified as a chloride if it gives

A. A white precipitate on addition of AgNO₃ and barium chloride solutions
B. A white precipiate when acidified with HCI, and then AgNO₃ solution added
C. A white precipitate when acidified with dilute HNO₃ and then AgNO₃ solution added
D. A white precipitate when acidified with dilute H₂SO₄ and then barium nitrate solution added
E. A pungent smell of chlorine gas when dilute HCI and MnO₂ are added