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 11:

  Zn + H₂ SO₄ → ZnSO₄ + H₂

  In the above reaction how much Zinc will be left of 1.0 M of H₂SO?

  [Zn =65, s = 32, O = 16, H = 1]

  Options:
  A) 1.35g
  B) 1.00g
  C) 0.70g
  D) 0.65g
  E) 0.00g
  Show Answer
  The correct answer is A .
• Question 12:

  

  The IUPAC nomenclature of the compound above is

  Options:
  A) 2-bromo-3-chlorobutanol
  B) 3-bromo-2-chlorobutanol
  C) 3-chloro-2-bromobutanol
  D) 2-chloro-3-bromobutanol
  Show Answer
  The correct answer is B .
• Question 13: Environmental pollution is worsened by the release from the automobile exhaust of Options:
  A) water vapour
  B) steam
  C) smoke
  D) heavy metals
  E) steam and smoke
  Show Answer
  The correct answer is D .
• Question 14: Which of the following represents an aromatic compound? Options:
  A) C₆H₅OH
  B) C₆H₁₂
  C) C₆H₉OH
  D) C₆H₈
  Show Answer
  The correct answer is A .
• Question 15:

  Temp (°C)	25	35	45
  Time (seconds)	72	36	18

  The times taken for iodine to be liberated in the reaction between sodium thiosulphate and hydrochloric acid at various temperature are as follows. These results suggest that

  Options:
  A) for a 10^o rise in temperature, rate of reaction is double
  B) for a 10 ^o rise in temperature, rate of reaction is halved
  C) time taken for iodine to appear does not depend on temperature
  D) for a 10 ^o rise in temperature rate of reaction is tripled
  Show Answer
  The correct answer is A .
• Question 16:

  In a reaction: SnO + 2C → Sn + 2CO, the mass of coke containing 80% carbon required to reduce 0.302 kg of pure tin oxide is?

  (Sn - 119, O - 16, C - 12).

  Options:
  A) 0.40 kg
  B) 0.20 kg
  C) 0.06 kg
  D) 0.04 kg
  Show Answer
  The correct answer is C .
• Question 17:

  The heat of reaction can be determined experimentally using a device called a

  Options:
  A) Calorimeter
  B) Barometer
  C) Spectrometer
  D) Thermometer
  Show Answer
  The correct answer is A .
• Question 18: Calculate the relative molecular mass of Limestone CaCO3, (Ca = 40, C =12, O = 16) Options:
  A) 56
  B) 100
  C) 76
  D) 90
  Show Answer
  The correct answer is B .
• Question 19: Which of the following is NOT correct test for the named organic compound in each case? Options:
  A) Butanoic acid solution gives effervescence with Na₂CO₃ solution
  B) Glucose when reacted with Na₂CrO₄ at 0°C will show immediate discharge of colour
  C) When but-2-ene is reacted with dilute solution of KMnO₄ the purple colour of KMnO is discharged readily even room temperature
  D) When butan-2-ol is boiled with butanoic acid with a drop of concentrated H₂SO₄ a sweet smelling liquid is produced
  Show Answer
  The correct answer is B .
• Question 20: Calculate the quantity of electricity in coulombs required to liberate 10g of copper from a copper compound[Cu=64, F = 96500 Cmol^-1] Options:
  A) 32395.5
  B) 30156.3
  C) 60784.5
  D) 15196.5
  Show Answer
  The correct answer is B .