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 21: Gunpower is made from charcoal, sulphur and potassium trioxonitrate (V) The salt in the mixture performs the function of Options:
  A) an oxidant
  B) a reductant
  C) a solvent
  D) a catalyst
  Show Answer
  The correct answer is A .
• Question 22: 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 23:

  The metal used to recover copper from a solution of copper sulphateis?

  Options:
  A) Na
  B) Ag
  C) Hg
  D) Fe
  Show Answer
  The correct answer is D .
• Question 24: When iron is exposed to moisture and it rusts, the value of ΔG for the reaction is Options:
  A) neutral
  B) zero
  C) positive
  D) negative
  Show Answer
  The correct answer is D .
• Question 25: Polystyrene is widely used as packaging materials for fragile objects during transportation because of its Options:
  A) ligjtness
  B) low density
  C) high density
  D) high compressibility
  Show Answer
  The correct answer is D .
• Question 26: In what way is equilibrium constant for the forward reaction related to that of the reversed reaction? Options:
  A) The additional of the two is expected to be one
  B) The product of the two is expected to be one
  C) The two equilibrium constants are identical
  D) The product of the two is always greater than one
  Show Answer
  The correct answer is A .
• Question 27:

  The nucleus of an atom consists of?

  Options:
  A) Electrons and neutrons
  B) Electrons and protons
  C) Protons and neutrons
  D) None of the above
  Show Answer
  The correct answer is C .
• Question 28: Which of the following classes of organic compounds undergoes rapid oxidation with bromine water? Options:
  A) alcohols
  B) alkenes
  C) carboxylic acids
  D) esters
  E) alkanes
  Show Answer
  The correct answer is B .
• Question 29: Which of the following oxides of nitrogen is unstable in air? Options:
  A) NO₂
  B) NO
  C) N₂O₄
  D) N₂O_5-
  Show Answer
  The correct answer is B .
• Question 30:

  200cm${}^3$ of 0.50mol/dm${}^3$ solution of calcium hydrogen trioxocarbonate (IV) is heated. The maximum weight of solid precipitated is

  Options:
  A) 10g
  B) 25g
  C) 20g
  D) 15g
  Show Answer
  The correct answer is A .