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 1341: Which of the following represents the balanced equation for the reaction of copper with concentrated trioxonitrate (V) acid? Options:
  A) Cu _(s) + 2HNO _3(aq) → Cu (NO ₃) _2(aq) + H _2(g)
  B) Cu _(s) + 4HNO _3(aq) → Cu (NO ₃) _2(aq) + 2H ₂O ₍₁₎ + 2NO _2(g)
  C) 3Cu _(s) + 8HNO_3(aq) → 3Cu (NO₃)_2(aq) + 4H₂O₍₁₎ + 2NO_(g)
  D) 3Cu_(s) + 4HNO_3(aq) → 3Cu(NO ₃) _2(aq) + 2H ₂O ₍₁₎ + 2NO _(g)
  Show Answer
  The correct answer is B .
• Question 1342: A mixture of common salt, ammonium chloride and barium sulphate can best be separated by Options:
  A) addition of water followed by filtration then sublimation
  B) addition of water followed by sublimation then filtration
  C) sublimation followed by addition of water then filtration
  D) fractional distillation
  E) fractional crystallization
  Show Answer
  The correct answer is C .
• Question 1343:

  Na₂CO_3(g) + 2HCl_(aq) → 2NaCl_(aq) + H₂O_(l) + CO_2(g)

  How many moles of sodium trioxocarbonate (IV) are there in a 25 cm³ solution which required 10cm³ of 0.05 mol dm^-3 hydrochloric acid solution to neutralize it?

  Options:
  A) 1.000 mole
  B) 0.100 mole
  C) 0.010 mole`
  D) 0.111 mole
  Show Answer
  The correct answer is C .
• Question 1344:

  0.0075 mole of calcium trioxocarbonate (IV) is added to 0.015 mole of a solution of hydrochloric acid. The volume of gas evolved at s.t.p is

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

  Options:
  A) 224cm³
  B) 168cm³
  C) 112cm³
  D) 100cm³
  Show Answer
  The correct answer is B .
• Question 1345: Which of the following statements is correct about the average kinetic energy of the molecules of a gas? Options:
  A) It increase with increase in pressure
  B) It increase at constant temperature
  C) It increase with increase in temperature
  D) It increase with increase in volume
  Show Answer
  The correct answer is C .
• Question 1346:

  

  2-methylbut-2-ene has the structure

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is D .
• Question 1347:

  Beryllium and Aluminium have similar properties because they

  Options:
  A) are both metals
  B) belong to the same group
  C) belong to the same period
  D) are positioned diagonally to each other
  Show Answer
  The correct answer is D .
• Question 1348: The solution with the lowest pH value is Options:
  A) 5 ml of (m/10) HCL
  B) 10 ml of (m/10) HCL
  C) 15 ml of (m/5) HCL
  D) 20 ml of (m/8) HCL
  Show Answer
  The correct answer is A .
• Question 1349: Consider the following equation H₂O + 2Fe²⁺ + Cl₂ ↔ 2Fe³⁺ + 2Cl^- + H₂O. The only ion which behaves as an oxidising agent is Options:
  A) Fe²⁺
  B) Cl₂
  C) Fe³⁺
  D) Cl^-
  E) H₂O
  Show Answer
  The correct answer is B .
• Question 1350:

  

  Use the option above to answer this question. Which is the correct set of results for tests conducted respectively on fresh lime juice and ethanol.

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