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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 6:
Detergents are more advantageous than soaps in hard water districts because
  • A On treatment with hard water they either form soluble calcium salts or do not react with calcium ion
  • B On treatment with hard water they form soluble calcium salts
  • C On treatment with hard water they form sodium salts
  • D On treatment with hard water they are converted into soaps
  • E On treatment with hard water they form more lather than soaps does
View Answer & Explanation
Question 7:
When sodium nitrate dissolves in water, ∆H is positive. This means that?
  • A The reaction is catalysed
  • B The reaction is complete
  • C The reaction is exothermic
  • D The reaction is endthermic
  • E Sodium nitrate is highly soluble in water
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Question 8:
9.8g of solid potassium chlorate (KCIO3) were added to 40 cm3 of water and heated to dissolve all the solid. As he solution cooled, crystals of potassium chlorate started forming at 60°C. The solubility of potassium chlorate at 66°C is therefore?
  • A 24.5 mole per dm<sup style='font-size: smaller;'>3</sup>
  • B 0.2 mole per dm<sup style='font-size: smaller;'>3</sup>
  • C 10.0 mole per dm<sup style='font-size: smaller;'>3</sup>
  • D 20.0 mole per dm<sup style='font-size: smaller;'>3</sup>
  • E 2.0 mole per dm<sup style='font-size: smaller;'>3</sup>
View Answer & Explanation
Question 9:
3. 06 g of a sample of potassium trioxochlorate (V) (KCIO) was required to make a saturated solution with 10cm3 of water at 25oC. The solubility of the salt at 25oC is [K =39, Cl = 35.5, O = 16]
  • A 5.0 moles dm<sup style='font-size: smaller;'>3</sup>
  • B 3.0 moles dm<sup style='font-size: smaller;'>3</sup>
  • C 2.5 moles dm<sup style='font-size: smaller;'>3</sup>
  • D 1.0 molesv
  • E 0.5 moles dm<sup style='font-size: smaller;'>3</sup>
View Answer & Explanation
Question 10:
When sodium dioxonitrate (lll) (NaNO2) dissolves in water, ∆H is positive. The process of dissolution is
  • A Exothermic
  • B Endothermic
  • C Isothermal
  • D Isomeric
  • E Hygroscopic
View Answer & Explanation