Jamb Chemistry 1979 Past Questions and Answers

Question 36:

• 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

Question 37:

• JAMB 1979

Hydrogenation may be effected by

A. The removal of hydrogen from an alkane in the presence of a catalyst
B. The addition of hydrogen to an alkane in the presence of a catalyst
C. The addition of hydrogen to an alkyne
D. The removal of hydrogen from an alkyne
E. The addition of hydrogen to an ethyl alcohol

Question 38:

• JAMB 1979

Two metallic ions associated with hard water are

A. Copper and zinc
B. Magnesium and silver
C. Calcium and magnesium
D. Potassium and tin
E. Sodium and lead

Question 39:

• JAMB 1979

Bronze is an alloy of

A. Copper, zinc and nickel
B. Aluminium and copper
C. Copper and zinc
D. Tin and zinc
E. Tin and copper

Question 40:

• JAMB 1979

Phosphorus burns in oxygen according to the equation P₄ + 50₂ → P₄O₁₀. How many litres of oxygen will be required at S.T.P for complete oxidation of 12.4g of phosphorus? [P = 31,O = 16 and molar volume of a gas at S.T.P = 22.4 litres]

A. 5. 20
B. 11. 20
C. 2. 24
D. 20. 20
E. 6. 20