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Wednesday, 17 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 136:
An iron ore is known to contain 70.0% Fe2O3. The obtain from 80kg of the ore is?
(Fe = 56, O = 16)
  • A 35.0 kg
  • B 39.2 kg
  • C 70.0 kg
  • D 78.4 kg
View Answer & Explanation
Question 137:
A quantity of air was passed through a weighed amount of alkaline pyrogallol. An increase in the weight of the pyrogallol would result from the absorption of?
  • A Nitrogen
  • B Neon
  • C Argon
  • D Oxygen
View Answer & Explanation
Question 138:
Which of the following ions is a pollutant in drinking water even in trace amounts?
  • A Ca<sup style='font-size: smaller;'>2+</sup>
  • B Hg<sup style='font-size: smaller;'>2+</sup>
  • C Mg<sup style='font-size: smaller;'>2+</sup>
  • D Fe<sup style='font-size: smaller;'>2+</sup>
View Answer & Explanation
Question 139:
How many structural isomers can be written for the alkyl bromide, C4H9Br?
  • A 3
  • B 4
  • C 6
  • D 8
View Answer & Explanation
Question 140:
Which of the following equimolar solutions, Na2CO3 Na2 SO4CI FeCI3 CH3COONa,
have pH greater than 7?
  • A FeCI <sub style='font-size: smaller;'>3</sub> and NH <sub style='font-size: smaller;'>4</sub>CI
  • B Na<sub style='font-size: smaller;'>2</sub>CO<sub style='font-size: smaller;'>3</sub>, CH<sub style='font-size: smaller;'>3</sub>COONa and Na,Na<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub>
  • C Na<sub style='font-size: smaller;'>2</sub>CO<sub style='font-size: smaller;'>3</sub> and CH<sub style='font-size: smaller;'>3</sub>COONa
  • D FeCI<sub style='font-size: smaller;'>3</sub>, CH<sub style='font-size: smaller;'>3</sub>COONa and NH<sub style='font-size: smaller;'>4</sub>CI
View Answer & Explanation