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Saturday, 13 June 2026
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Chemistry Past Questions and Answers

Topic: Separation of mixtures and purification of chemical substances

Jamb Chemistry Questions - Separation of mixtures and purification of chemical substances

Question 11:
The cost of discharging 6.0g of a divalent metal, X from its salt is What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?
[X = 63, Y = 27, 1F = 96,500C]
  • A N12.00
  • B N27.00
  • C N63.00
  • D N95.00
View Answer & Explanation
Question 12:
X is a substance which liberates CO2 on treatment with concentrated H2SO4. A warm solution of X can decolorize acidified KMnO4. X is
  • A HCOOH
  • B NaH CO<sub style='font-size: smaller;'>3</sub>
  • C FeCO<sub style='font-size: smaller;'>3</sub>
  • D H<sub style='font-size: smaller;'>2</sub>C<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>4</sub>
View Answer & Explanation
Question 13:
The pH of four solutions W, X, Y, Z are 4, 6, 8, 10 respectively, therefore
  • A None of these solutions is acidic
  • B The pH of Y is made more acidic by addition of distilled water
  • C Z is the most acidic solution
  • D W is the most acidic solution
  • E X is neutral
View Answer & Explanation
Question 14:
Brass and bronze are both metallic alloys. Which of the following constituents is common to both alloys?
  • A Tin
  • B Zinc
  • C Copper
  • D Lead
  • E Aluminium
View Answer & Explanation
Question 15:
Which of the following compounds will form a solution if exposed to air?
  • A Na<sub style='font-size: smaller;'>2</sub>CO<sub style='font-size: smaller;'>3</sub>.10H<sub style='font-size: smaller;'>2</sub>O
  • B NaNO<sub style='font-size: smaller;'>3</sub>
  • C CuSO<sub style='font-size: smaller;'>4</sub>
  • D CaCl<sub style='font-size: smaller;'>2</sub>
  • E Na<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub>.10H<sub style='font-size: smaller;'>2</sub>O
View Answer & Explanation