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 1031:

  Which of the following is a form of calcium carbonate?

  I. limestone
  II. marble
  III. chalk
  Iv. egg-shells

  Options:
  A) I only
  B) I, II and IV
  C) I and II only
  D) I, II, III, and IV
  Show Answer
  The correct answer is D .
• Question 1032:

  Chromatography is used to separate components of mixture which differ in their rates of ?

  Options:
  A) diffusion
  B) migration
  C) reaction
  D) sedimentation
  Show Answer
  The correct answer is B .
• Question 1033: Which of the following salts will turn blue litmus red? Options:
  A) Sodium tetrahydroxozincate (ll)
  B) Potassium hydrogentetraoxosulphate (lV)
  C) Sodium trioxocarbonate (lV)
  D) Zinc chloride hydroxide
  Show Answer
  The correct answer is B .
• Question 1034: The characteristic colour of the flame shown when a copper sail moistened with concentrated hydrochloric acid on a platinum wire is put on bunsen burner is Options:
  A) lilac
  B) green
  C) yellow
  D) brick-red
  Show Answer
  The correct answer is B .
• Question 1035: The modern process of manufacturing steel for iron is by Options:
  A) treatment with acids
  B) oxidation
  C) blast reduction
  D) treatment with alkanal
  Show Answer
  The correct answer is C .
• Question 1036:

  The number of electrons in the valence shell of an element of atomic number 14 is?

  Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is D .
• Question 1037: When sodium is added to ethanol, the products are? Options:
  A) sodium hydroxide and water
  B) sodium hydroxide and hydrogen
  C) sodium ethoxide and water
  D) sodium ethoxide and hydrogen
  Show Answer
  The correct answer is D .
• Question 1038:

  The percentage of water of crystallization in ZnSO₄.7H₂O is

  [Zn = 65, S = 32, O = 1, H = 1]

  Options:
  A) 33%
  B) 44%
  C) 55%
  D) 87%
  Show Answer
  The correct answer is B .
• Question 1039: The flame used by welders in cutting metals is Options:
  A) butane gas flame
  B) acetylene flame
  C) kerosene flame
  D) oxy-acetylene flame
  E) oxygen flame
  Show Answer
  The correct answer is D .
• Question 1040:

  What volume of oxygen is produced from the decomposition of 2 mole of KCIO₃ at s.t.p?

  [Molar volume of a gas at s.t.p = 22.4 dm³]

  Options:
  A) 22.4 dm³
  B) 33.6 dm³
  C) 44.8 dm³
  D) 67.2 dm³
  Show Answer
  The correct answer is D .