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Tuesday, 21 April 2026
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Chemistry Past Questions and Answers

Chemistry Questions

Question 76:
When each of the nitrates of Potassium, Magnesium and iron is heated,
  • A All the nitrates decompose to their oxides
  • B The nitrate of magnesium gives the nitrite and oxygen
  • C The nitrates of iron magnesium and iron give the oxides
  • D The nitrate of iron gives the nitrite and oxygen
  • E The nitrate of the magnesium is not decomposed
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Question 77:
Which of the following metals cannot replace hydrogen from water or steam?
  • A Sodium
  • B Magnesium
  • C Iron
  • D Calcium
  • E Copper
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Question 78:
A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by
  • A Boiling the water
  • B Adding excess calcium hydroxide
  • C Adding a calculated amount of calcium hydroxide
  • D Adding sodium carbonate
  • E Adding magnesium hydroxide
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Question 79:
During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,
  • A The litmus turns blue but no gas is evolved
  • B The litmus turns blue and oxygen is evolved
  • C The litmus turns blue and hydrogen is evolved
  • D The litmus turns red and oxygen is evolved
  • E The litmus turns red and then becomes colourless
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Question 80:
The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;
  • A Saponification
  • B Dehydration
  • C Esterification
  • D Hydrolysis
  • E Hydration
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