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: An increase in the pressure exerted on gas at a constant temperature results in Options:
  A) a decrease in the number of effective collisions
  B) a decrease in volume
  C) an increase in the average intermolecular distance
  D) an increase in volume
  Show Answer
  The correct answer is B .
• Question 52:

  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 53: 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 54: A difference between chemical and physical change is that in a chemical change Options:
  A) oxygen is consumed
  B) heat is supplied
  C) the reversible process occurs
  D) a new substance is formed
  Show Answer
  The correct answer is D .
• Question 55:

  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 56:

  

  The solubility curve of a solid X (molecular mass = 160) is as show above 1,000 cm³ of a saturated solution of X at 80^oC. The weight of X crystalized out would be

  Options:
  A) 10 g
  B) 12 g
  C) 14 g
  D) 16 g
  E) 18 g
  Show Answer
  The correct answer is D .
• Question 57:

  What is the IUPAC name for the compound CCl${}_4$?

  Options:
  A) Tetrahydrochloride
  B) Tetrachloromethane
  C) Carbon tetrachloride
  D) Chloroform
  Show Answer
  The correct answer is B .
• Question 58: The product formed at the the cathode during the electrolysis of sodium chloride solution with carbon electrodes is? Options:
  A) sodium
  B) chlorine
  C) hydrogen
  D) sodium hydroxide
  E) oxygen
  Show Answer
  The correct answer is C .
• Question 59:

  Which of the following statements about catalyst is false?

  Options:
  A) biological catalysts are called enzymes
  B) catalyst do not appear in the balanced equation
  C) catalyst reduce the activation energy for a reaction
  D) catalysts do not alter the mechanism of the reaction and never appear in the rate low
  Show Answer
  The correct answer is D .
• Question 60:

  The sulphide that is commonly used in coating electric fluorescent tubes is?

  Options:
  A) iron(ii)Sulphide
  B) tin(ii)sulphide
  C) Zinc Sulphide
  D) lead(iv) Sulphide
  Show Answer
  The correct answer is C .