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Friday, 02 October 2026
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Chemistry Past Questions and Answers

Topic: Crystallization

Jamb Chemistry Questions - Crystallization

Question 1:
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
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Question 2:
A substance S is isomorphous with another substance R. When a tiny crystals of S is added into a supersaturated solution of R?
  • A S dissolves in the solution
  • B Crystals of R are precipitated
  • C There is no observable change
  • D R and S react to generate heat
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Question 3:
Which of the following are produced when ammonium trioxonitrate (V) crystals are cautiously heated in a hard glass round bottomed flask?
  • A N<sub style='font-size: smaller;'>2</sub>O and steam
  • B NO<sub style='font-size: smaller;'>2</sub> and ammonia
  • C N<sub style='font-size: smaller;'>2</sub>O<sub style='font-size: smaller;'>2</sub> and NO<sub style='font-size: smaller;'>2</sub>
  • D NO and NO<sub style='font-size: smaller;'>2</sub>
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Question 4:
On recrystallization, 20g of magnesium tetraoxosuphate (IV) forms 41 g of magnesium tetraoxosulphate (IV) crystals, MgSO4. yH2O. The value of y is?
(Mg = 24, S = 32, O = 16, H = 1)
  • A 1
  • B 3
  • C 5
  • D 7
View Answer & Explanation
Question 5:
Helium is used in observation of ballons because it is?
  • A Light and combustible
  • B Light and non-combustible
  • C Heavy and combustible
  • D Heavy and non-combustible
View Answer & Explanation