Solubility - Jamb Chemistry Past Questions and Answers

Question 1:

• JAMB 1978

Consider the solubility curves of three salts X, Y and Z given in the diagram. If each solution of the salt contains 200 g, and is heated to 100^oC, which solution or solutions will deposit 100 g of the solute when suddenly cooled to 0^oC?

A. X only
B. Y only
C. Z only
D. X and Z
E. Y and Z

Question 2:

• JAMB 1978

An experiment test of the Law of conservation of Mass is illustrated in the diagram. In practice, the flask is weighed before and after reaction between solutions X and Y. Which of the following pairs of solutions will be unsuitable for the experiments

A. X = hydrochloric acid; Y = silver nitrate
B. X = barium chloride; Y = dilute sulphuric acid
C. X = hydrochloric acid; Y = sodium hydroxide
D. X = hydrochloric acid; Y = lead nitrate
E. X = hydrochloric acid; Y = sodium carbonate

Question 3:

• JAMB 1979

12 g of solid protassium chlorate (KCIO) were added to 40 g of water and heated to dissolve all the solid. As the solution cools, crystals of potassium chlorate at 66 ^oC. The solubility of potassium chlorate at 66 ^oC is therefore

A. 66
B. 33
C. 10
D. 20
E. 30

Question 4:

• JAMB 1979

Calcium hydroxide and ammonium chloride when heated together will give an important product. This compound may be obtained dry by

A. Dissolving it in water, recrystallizing it and then drying in the oven
B. Passing it through a concentrated aqueous solution of sodium hydroxide
C. Passing it through calcium oxide
D. Passing it through concentrated sulphuric acid
E. Passing it through anhydrous calcium choride

Question 5:

• JAMB 1980

A solution X on mixing with AgNO₃ solution, gives a white precipitate solution in NH₃. A Solution Y, when added to X, also gives a white precipiate which is soluble on boiling. Solution Y contains?

A. Ag⁺ion
B. Pb²⁺ion
C. Pb⁴⁺ion
D. Zn²⁺ion
E. Al³⁺ion