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Chemistry Past Questions and Answers

Jamb 1978 Chemistry Questions

Question 46:
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 100oC, which solution or solutions will deposit 100 g of the solute when suddenly cooled to 0oC?
  • A X only
  • B Y only
  • C Z only
  • D X and Z
  • E Y and Z
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Question 47:
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
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Question 48:
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
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