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 351:

  

  Use the figure above to answer this question. Which of the following compounds is an isomer of the compound

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is D .
• Question 352:

  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 .
• Question 353:

  At 2.0 atm pressure, the volume of a gas is 4.0 L. If the pressure is reduced to 1.0 atm while keeping the temperature constant, what will be the new volume of the gas?

  Options:
  A) 2.0 L
  B) 6.0 L
  C) 8.0 L
  D) 4.0 L
  Show Answer
  The correct answer is C .
• Question 354: Which of the following will have its mass increased when heated in air? Options:
  A) Helium
  B) Magnesium
  C) Copper pyrites
  D) Glass
  Show Answer
  The correct answer is B .
• Question 355: The gas that is used for the treatment of cancer is Options:
  A) Neon
  B) Radon
  C) Xenon
  D) Argon
  Show Answer
  The correct answer is B .
• Question 356:

  CH₃COOH_(aq) + OH^-_(aq) ↔ CH₃COO^-_(aq) + H₂O_(l)

  In the reaction above ,CH₃COO^-_(aq) is

  Options:
  A) conjugate base
  B) acid
  C) base
  D) conjugate acid
  Show Answer
  The correct answer is A .
• Question 357: Detergents are manufactured with straight hydrocarbon chains so as to make them Options:
  A) soluble
  B) biodegradable
  C) cheaper
  D) foamy
  Show Answer
  The correct answer is B .
• Question 358:

  The products of the thermal decomposition of ammonium trioxonitrate(v) are?

  Options:
  A) Nitrogen (I) Oxide and Water
  B) Ammonia and Oxide
  C) Nitrogen and Water
  D) Nitrogen (IV) Oxide and Water
  Show Answer
  The correct answer is A .
• Question 359: The order in which a mixture of sand, ammonium chloride and sodium chloride can be separated is Options:
  A) dissolution → dryness → filtration → evaporation
  B) filtration → sublimation → evaporation → dryness
  C) sublimation → dissolution → filtration → evaporation
  D) dissolution → filtration → sublimation → evaporation
  Show Answer
  The correct answer is C .
• Question 360: What is the molar mass of a substance, if 0.4 mole of the substance has a mass of 25.0g? Options:
  A) 62.5 g
  B) 40.0 g
  C) 6.3 g
  D) 2.5 g
  Show Answer
  The correct answer is A .