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 51: A side effect of soft water is that Options:
  A) it gives offensive taste
  B) excess calcium is precipitated
  C) it attacks lead contained in pipes
  D) it encourage the growth of bacteria
  Show Answer
  The correct answer is C .
• Question 52: Which volume of 0.5 M H ₂SO₄ will exactly neutralize 20 cm ³ of 0.1 M NaOH solution? Options:
  A) 2.0 cm ³
  B) 5.0 cm ³
  C) 6.8 cm ³
  D) 8.3 cm ³
  E) 10.4 cm ³
  Show Answer
  The correct answer is A .
• Question 53: Synthetic rubber obtained by the polymerization of chlorobutadiene in the presence of sodium is called? Options:
  A) teflon
  B) isoprene
  C) polythene
  D) neoprene
  Show Answer
  The correct answer is D .
• Question 54: The effect of the presence of impurities such as carbon and sulphur on iron is that they Options:
  A) give it high tensile strenght
  B) make it malleable and ductile
  C) increase its melting point
  D) lower its melting point
  Show Answer
  The correct answer is D .
• Question 55: Oil spillage in ponds and creeks can be cleaned up by? Options:
  A) burning off the oil layer
  B) spraying with detergent
  C) dispersal with compressed air
  D) spraying with hot water
  Show Answer
  The correct answer is B .
• Question 56: Which of these reagents can confirm the presence of a triple bond? Options:
  A) Bromine water
  B) Acidified KMnO₄
  C) Copper (I) chloride
  D) Bromine gas
  Show Answer
  The correct answer is C .
• Question 57:

  

  2HCI_(ag) + CaCO_{3(s) → CaCl2(s)} + CO _2(g) +H₂O₍₁₎

  From the reaction above, which of the curves in the diagram represents the production of carbon (IV) oxide as dilute HCI is added?

  Options:
  A) L
  B) M
  C) N
  D) P
  Show Answer
  The correct answer is B .
• Question 58:

  What volume of (dm${}^3$) of water will be added to 10dm${}^3$ of 2.0 mol/dm${}^3$ HCL acid solution to give a final solution of 0.5 mol/dm${}^3$?

  Options:
  A) 30
  B) 40
  C) 20
  D) 50
  Show Answer
  The correct answer is B .
• Question 59: Permanent hardness of water can be removed by Options:
  A) filtration
  B) adding slaked lime
  C) adding caustic soda
  D) boiling
  Show Answer
  The correct answer is C .
• Question 60: In the reaction E+F ↔ G+H, the backward reaction is favoured if the concentration of Options:
  A) F is increased
  B) E is increased
  C) E is reduced
  D) G is reduced
  Show Answer
  The correct answer is C .