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Friday, 14 August 2026
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Chemistry Past Questions and Answers

Topic: Separation processes

Jamb Chemistry Questions - Separation processes

Question 6:
In the preparation of ammonia, which of the following is used as the drying agent?
  • A CaO
  • B CaCI<sub style='font-size: smaller;'>2</sub>
  • C Conc. H<sub style='font-size: smaller;'>2</sub>SO<sub style='font-size: smaller;'>4</sub>
  • D P<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>5</sub>
  • E H<sub style='font-size: smaller;'>3</sub>PO<sub style='font-size: smaller;'>4</sub>
View Answer & Explanation
Question 7:
5cm3 of a saturated solution of sodium chloride at 30°C gave, on careful evaporation, 1.95g of solid salt. The solubility of sodium chloride at 30°C?
(Na = 23, Cl = 35.5)
  • A 5.00 mole dm<sup style='font-size: smaller;'>3</sup>
  • B 5.67 mole dm<sup style='font-size: smaller;'>3</sup>
  • C 6.00 mole dm<sup style='font-size: smaller;'>3</sup>
  • D 6.67 mole dm<sup style='font-size: smaller;'>3</sup>
  • E 7.00 mole dm<sup style='font-size: smaller;'>3</sup>
View Answer & Explanation
Question 8:
Sodium carbonate crystals on exposure to a dry atmosphere change to a white powder. This phenomenon is known as?
  • A Deliquescence
  • B Hygroscopy
  • C Oxidation
  • D Efforescence
  • E Sublimation
View Answer & Explanation
Question 9:
The solubility curve of a solid X (molecular mass = 160) is as show above. 1,000 cm3 of a saturated solution of X at 80°C is cooled to 40°C . The weight of X crystalized out would be
  • A 10 g
  • B 12 g
  • C 14 g
  • D 16 g
  • E 18 g
View Answer & Explanation
Question 10:
Some copper (ll) sulphate pentahydrate (CuSO4 5H2O), was heated at 120 oC with the following results. Wt of crucible = 10.00 g; Wt of crucible + CuSO4 5H2O =14.98g; Wt of crucible + residue = 13.54 g. How many molecules of water of crystalization were lost?
[H = 1, Cu = 63.5, O = 16, S = 32]
  • A 1
  • B 2
  • C 3
  • D 4
  • E 5
View Answer & Explanation