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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 11:
Water is said to be 'hard' if it
  • A Easily forms ice
  • B Has to be warmed before sodium chloride dissolves in it
  • C Froms an insoluble scum with soap
  • D Contains nitrates
  • E Contains sodium ions
View Answer & Explanation
Question 12:
When marble is heated to about 1473 K, another white solid is obtained which reacts vigorously with water to give an alkaline solution. The solution contains?
  • A NaOH
  • B KOH
  • C Mg(OH)<sub style='font-size: smaller;'>2</sub>
  • D Zn(OH)<sub style='font-size: smaller;'>2</sub>
  • E Ca(OH)<sub style='font-size: smaller;'>2</sub>
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Question 13:
In the solubility curve above, water at 98oC is saturated with KCL and KCIO 3 What is the percentage of KCL impurity in the crystals formed when the solution is cooled to 30 oC?
  • A 51.5
  • B 45.5
  • C 34.5
  • D 26.5
View Answer & Explanation
Question 14:
In the purification of town water supply, alum is used principally to?
  • A Kill bacteria
  • B Control the pH of water
  • C Improve the taste of the water
  • D Coagulate small pasrticles of mud
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Question 15:
Which of the following water samples will have the highest titre value when titrated for the Ca2+ ions using soap solution?
  • A Permanently hard water after boiling
  • B Emporarily hard water after boiling
  • C Rain water stored in a glass jar for two years
  • D Permanent hard water passed through permuitit
View Answer & Explanation