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Saturday, 15 August 2026
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Chemistry Past Questions and Answers

Topic: Water as a solvent

Jamb Chemistry Questions - Water as a solvent

Question 16:
The ion that may be assumed to have negligible concentration in a sample of water that lathers readily with soap is?
  • A Mg<sup style='font-size: smaller;'>+</sup>
  • B K<sup style='font-size: smaller;'>+</sup>
  • C CO<sub style='font-size: smaller;'>2</sub><sup style='font-size: smaller;'>2-</sup>
  • D HCO<sub style='font-size: smaller;'>3</sub>
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Question 17:
Mortar is NOT used for under-water construction because
  • A It hardens by lose of water
  • B Its hardening doe not depend upon evaporation
  • C It requires concrete to harden
  • D It will be washed away by the flow of water
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Question 18:
The solubility in moles per dm3 of 20g of CuSO4 dissolve in 100 of water at 180°C is?
(Cu = 63.5, S = 32, O = 16)
  • A 0.13
  • B 0.25
  • C 1.25
  • D 2.00
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Question 19:
The solubility of copper (II) tetraoxosulphate (Iv) is 75g in 100g of water at 100°C and 25g in 100g of water at 30°C. What mass of the salt would crystallize, if 50g of copper (II) tetraoxosulphate (VI) solution saturated at 100°C were cooled to 30°C ?
  • A 57.5
  • B 42.2
  • C 28.6
  • D 14.3
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Question 20:
A sample of temporary hard water can be prepared in the laboratory by?
  • A Disolving calcium chloride in distilled water
  • B Saturating lime water with carbon (IV) oxide
  • C Saturating distilled water with calcium hydroxide
  • D Dissolving sodium hydrogen trioxocarbonate (IV) in some distilled water
View Answer & Explanation