Jamb Chemistry 1978 Past Questions and Answers

Question 46:

• 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 47:

• 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 48:

• JAMB 1978

Five compounds R,T,W,X and Y form the following compounds: a basic hydride R.H, an acidic hydride YH, atmospheric oxide W₂O₃, XO₂. which of the elements is an alkali

A. R
B. T
C. W
D. X
E. Y