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 1051:

  What is the concentration of a solution containing 2g of NaOH in 100cm³ of solution?
  [Na = 23, O = 16, H = 1]

  Options:
  A) 0.40 mol dm^-3
  B) 0.50 mol dm^-3
  C) 0.05 mol dm^-3
  D) 0.30 mol dm^-3
  Show Answer
  The correct answer is B .
• Question 1052: If the ONLY pollutants found in the atmosphere over a city are oxides of nitrogen, suspended lead compounds. carbon monoxide and high levels of methane, the probable source(s) of the pollution must be? Options:
  A) automobile exhaust and biological decomposition
  B) combustion of coal and automobile exhaust
  C) biological decomposition only
  D) combustion of coal, automobile exhaust and biological decomposition
  E) combustion of coal and biological decomposition
  Show Answer
  The correct answer is B .
• Question 1053:

  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 1054: The oxidation state of oxygen in tetraoxosulphate(IV) acid is Options:
  A) -4
  B) +4
  C) -2
  D) +2
  Show Answer
  The correct answer is C .
• Question 1055: A burning candle produces water and Options:
  A) Carbon (II) oxide
  B) Carbon (IV) oxide
  C) Oxygen
  D) Hydrogen
  Show Answer
  The correct answer is B .
• Question 1056: A gas that is not associated with global warming is Options:
  A) CO₂
  B) SO₃
  C) CH₄
  D) H₂
  Show Answer
  The correct answer is A .
• Question 1057:

  From the graph above, it may be concluded that

  Options:
  A) AgNO${}_3$ is probably not soluble at 1100
  B) NaCl is insoluble in water
  C) Pb(NO${}_3$)${}_2$ is more soluble than KCIO${}_3$
  D) The solubility of KCIO${}_3$ exceeds that of NaCl at all temperature
  Show Answer
  The correct answer is C .
• Question 1058: If an equilibrium reaction has ΔH > 0, the reaction will proceed favourably in the forward direction at Options:
  A) High temperature
  B) Any temperature
  C) Low temperature
  D) Minimum temperature
  Show Answer
  The correct answer is A .
• Question 1059:

  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 1060:

  

  Use the options above to answer this question. Which is the structural formula for pent-2-enoic acid?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is C .