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 1501:

  When the end alkyl groups of ethyl ethanoate are interchanged, the compound formed is

  Options:
  A) propylmethanoate
  B) ethylpropanoate
  C) methyl ethanoate
  D) methyl propanoate
  Show Answer
  The correct answer is B .
• Question 1502:

  A basic postulate of the kinetic theory of gases is that the molecules of a gas move in straight lines between collisions. This implies that

  Options:
  A) collisions are perfectly elastic
  B) forces of repulsion exist
  C) forces of repulsion and attraction are in equilibrium
  D) collisions are inelastic
  Show Answer
  The correct answer is B .
• Question 1503: 3.0g of a mixture of potassium carbonate and potassium chloride were dissolved in a 25cm³ of this solution required required 40.00cm₃ of 0.1M HCl for neutralization. What is the percentage by weight of K₂CO₃ in the mixture. (K = 39, O = 16, C = 12) Options:
  A) 60
  B) 72
  C) 82
  D) 89
  E) 92
  Show Answer
  The correct answer is E .
• Question 1504:

  What is the principal ore of iron, from which iron is extracted?

  Options:
  A) Calcite
  B) Bauxite
  C) Magnetite
  D) Hematite
  Show Answer
  The correct answer is D .
• Question 1505:

  Which of the following is used to power steam engines?

  Options:
  A) lubricating oil
  B) coal
  C) bitumen
  D) diesel oil
  Show Answer
  The correct answer is B .
• Question 1506: Group VII elements are Options:
  A) monoatmic
  B) good oxidizing agents
  C) highly electropositive
  D) electron donors
  Show Answer
  The correct answer is B .
• Question 1507: Three drops of a 1.0 mol dm^-3 solution of NaOH are added to 20 cm³ of a solution of pH 8.4. The pH of the resulting solution will be Options:
  A) Close to that of pure water
  B) Unaltered
  C) Greater than 8.4
  D) Less than 8.4
  Show Answer
  The correct answer is C .
• Question 1508: What mass of sodium carbonate solution is in 500 cm³ of 0.1 molar sodium carbonate solution?(Na = 23, C = 12, O = 16) Options:
  A) 10.6 g
  B) 5.3 g
  C) 500 g
  D) 10 g
  E) 20 g
  Show Answer
  The correct answer is B .
• Question 1509:

  

  In the solubility curve above, water at 98^oC is saturated with KCL and KCIO₃ What is the percentage of KCL impurity in the crystals formed when the solution is cooled to 30 ^oC?

  Options:
  A) 51.5
  B) 45.5
  C) 34.5
  D) 26.5
  Show Answer
  The correct answer is C .
• Question 1510:

  C_(s) + 2S_(g) → CS_2(g)

  ΔH = +89 kJ mol^-1

  The chemical equation above implies that

  Options:
  A) each of carbon and sulphur has 89 kJ of energy
  B) both carbon and sulphur contribute 89 kJ of energy
  C) 89 kJ of energy is released
  D) 89 kJ of energy is absorbed
  Show Answer
  The correct answer is D .