Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 701: The metal whose ore can be concentrated by passing it through a magnetic separator is Options:
  A) Zn
  B) Sn
  C) Cn
  D) Ca
  Show Answer
  The correct answer is B .
• Question 702: Terylene is synthesized from ethane- 1, 2-diol and benzene - 1, 4-dicarboxylic acid by? Options:
  A) addition reaction
  B) condensation reaction
  C) elimination reaction
  D) substitution reaction
  Show Answer
  The correct answer is B .
• Question 703: Ca(OH)_2(s) + 2NH₄Cl_(g) → CaCl_2(s) + 2H₂O_2(l) + X. In the reaction above X is Options:
  A) NO₂
  B) NH₃
  C) N₂O
  D) NO₂
  Show Answer
  The correct answer is B .
• Question 704: The scale of a chemical balance is made of iron plate and coated with copper electrolytically because Options:
  A) iron is less susceptible to corrosion than copper
  B) copper is twice as less susceptitible to corrosion as iron
  C) copper is less susceptible to corrosion than iron
  D) copper and iron are equally susceptible to corrosion
  Show Answer
  The correct answer is C .
• Question 705:

  Proteins in acid solution undergo?

  Options:
  A) Substitution
  B) Fermentation
  C) Hydrolysis
  D) Polymerisation
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  The correct answer is C .
• Question 706: If y is an oxidizing agent that reacts with a reducing agent, Z, which of the following is correct? Options:
  A) Y increases in oxidation number
  B) Y becomes reduced
  C) Z loses protons
  D) Z gains protons
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  The correct answer is B .
• Question 707:

  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]

  Options:
  A) 1
  B) 2
  C) 3
  D) 4
  E) 5
  Show Answer
  The correct answer is D .
• Question 708: In dilute solution the heat of the reaction NaOH + HCl = NaCl + H2O is - 57.3kJ. Therefore the heat of the reaction 2NaOH + H₂SO₄ $\to$ Na₂SO₄ + 2H₂O is Options:
  A) + 28.65 kJ
  B) - 28.65KJ
  C) + 57.3KJ
  D) - 114.6 KJ
  E) - 229.2 KJ
  Show Answer
  The correct answer is D .
• Question 709:

  Which of the following are mixtures?

  i. Petroleum
  ii. Rubber latex
  iii. Vulcanizer's solution
  iv. Carbon (II) sulphide

  Options:
  A) i, ii and iii
  B) i, ii and iv
  C) i and ii only
  D) i and iv
  Show Answer
  The correct answer is A .
• Question 710: Smoke consist of? Options:
  A) solid particles dispersed in liquid
  B) solid or liquid particles dispersed in gas
  C) gas or liquid particles dispersed inliquid
  D) liquid particles dispersed inliquid
  Show Answer
  The correct answer is B .