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Monday, 17 August 2026
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Chemistry Past Questions and Answers

Topic: Water as a solvent

Jamb Chemistry Questions - Water as a solvent

Question 56:
Hardness of water is mainly due to the presence of
  • A Calcium hydroxide or magnesium hydroxide
  • B Calcium trioxocarbonate (IV) or calcium tetraoxosulphate (VI)
  • C Sodium hydroxide or magnesium hydroxide
  • D Calcium chloride or sodium chloride salts
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Question 57:
If 24.4 g of lead (ll) trioxonitrate (V) were dissolved in 42 g of distilled water at 20oC; calculate the solubility of the solute in gdm-3.
  • A 581.000.
  • B 0.581
  • C 5.810
  • D 58.100
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Question 58:
In a water body, too much sewage leads to
  • A A decrease in the temperature of the water which cause in death of aquatic animals
  • B An increase in the number of aquatic animals in the water
  • C An increase in the bacterial population which reduces the level of oxygen in the water
  • D A decrease in the bacterial population which increases the level of oxygen in the water
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Question 59:
10.0 dm3 of water was added to 2.0 mol dm-3 of 2.5dm3 solution of HCl. What is the concentration of the final solution in mol dm-3?
  • A 0.4
  • B 8.0
  • C 2.0
  • D 0.5
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Question 60:
Water is said to be temporarily hard when it contains
  • A Ca (HCO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>2</sub> and Mg (HCO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>2</sub> salts
  • B Ca (HCO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>2</sub> and CaCO<sub style='font-size: smaller;'>3</sub> SALTS
  • C Mg(HCO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>2</sub> and CaSO<sub style='font-size: smaller;'>4</sub> salts
  • D CaSO<sub style='font-size: smaller;'>4</sub> and Ca(HCO<sub style='font-size: smaller;'>3</sub>)<sub style='font-size: smaller;'>2</sub> salts
View Answer & Explanation