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 31: Natural water collected from rivers and ponds contain oxygen, carbon (IV) oxide and Options:
  A) nitrogen
  B) hydrogen
  C) chlorine
  D) sulphur
  E) oxide
  Show Answer
  The correct answer is A .
• Question 32: Which of the following alkanes has the highest boiling point? Options:
  A) Pentane
  B) Ethane
  C) Propane
  D) Methane
  Show Answer
  The correct answer is A .
• Question 33:

  At room temperature and standard pressure, chlorine gas is in which state of matter?

  Options:
  A) Plasma
  B) Solid
  C) Liquid
  D) Gas
  Show Answer
  The correct answer is D .
• Question 34: 20 cm³ of 1.0 molar NH₄OH solution when neutralized with 20.05cm³ of 0.1 molar HCl liberated -102 joules of heat. Calculate the heat of neutralization of NH₄OH? Options:
  A) -51.O KJ mol^-
  B) +57.3 KJ mol^-
  C) +57.O KJ mol^-
  D) +51.0 KJ mol^-
  Show Answer
  The correct answer is A .
• Question 35: The dissolution of common salt in water is a physical change because Options:
  A) the salt can be obtained by crystallization
  B) the salt can be recovered by the evaporation of water
  C) heat is not generated during mixing
  D) the solution will not boil at 100^oC
  Show Answer
  The correct answer is C .
• Question 36: The Arrhenius equation expresses the relationship between the speed of a reaction and its Options:
  A) Molecular collision
  B) Heat of reaction
  C) Catalyst
  D) Activation energy
  Show Answer
  The correct answer is A .
• Question 37: The final products of the reaction between methane and chlorine in the presence of ultraviolet light are hydrogen chloride and Options:
  A) tricloromethane
  B) dichloromethane
  C) tetrachloromethane
  D) chloromethane
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  The correct answer is C .
• Question 38: The acid anhydride that will produce weak acid in water is Options:
  A) SO₃
  B) NO₂
  C) SO₂
  D) CO₂
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  The correct answer is D .
• Question 39: 3Cl₂ + 2NH₃ $\to$ N₂ + 6HCl. In the above reaction, ammonia acts as Options:
  A) a reducing agent
  B) an oxidizing agent
  C) an acid
  D) a catalyst
  E) a dry agent
  Show Answer
  The correct answer is A .
• Question 40: The ability of ionic solids is generally due to the? Options:
  A) negative electron affinity of most atoms
  B) crystal lattice forces
  C) electron pair sharing
  D) positive ionization potentials
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  The correct answer is B .