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 1641: The colour of litmus in an alkaline medium is Options:
  A) Red
  B) Yellow
  C) Pink
  D) Blue
  Show Answer
  The correct answer is D .
• Question 1642: When iron is exposed to moist air, it gradually rusts. This is due to the formation of Options:
  A) hydrate iron (III) oxide
  B) anhydrous iron (III) oxide
  C) anhydrous iron (II) oxide
  D) hydrate iron (II) oxide
  Show Answer
  The correct answer is A .
• Question 1643: A particle that contains a protons, 10 neutrons and 10 electrons is Options:
  A) positive ion
  B) neutral atom of a metal
  C) neutral atom of a non-metal
  D) negative ion
  Show Answer
  The correct answer is D .
• Question 1644: Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution? Options:
  A) Cu²⁺ + 2e^- → Cu(s)
  B) 2Cl^- -2e → Cl₂
  C) Cu_(s) -2e → Cu²⁺_(aq)
  D) Cu²⁺_(aq) + 2Cl^-_(aq) → CuCl_2(aq)
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  The correct answer is A .
• Question 1645: Sugar is separated from its impurities by Options:
  A) precipitation
  B) crystallization
  C) distillation
  D) evaporation
  Show Answer
  The correct answer is B .
• Question 1646: Clothes should be properly rinsed with water after bleaching because Options:
  A) the bleach decolourizes the clothes
  B) chlorine reacts with fabrics during bleaching
  C) the clothes are sterilized during bleaching
  D) hydrogen chloride solution is produced during bleaching
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  The correct answer is D .
• Question 1647: What will happen if an aluminium spoon is used to stir a solution of iron (II) trioxonitrates (V)? Options:
  A) The spoon will be oxidized while the iron (II) ions will be reduced to the metal
  B) The spoon will increase in size
  C) The spoon will be reduced while the iron (II) ions will be oxidized
  D) The spoon will be reduced
  Show Answer
  The correct answer is A .
• Question 1648: The atom of an element X is represented as ${}_z^{y}X$. The basic chemical properties of X depend on the value of Options:
  A) Y
  B) Z
  C) Y - Z
  D) Z - Y
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  The correct answer is B .
• Question 1649: Addition of an aqueous solution of a salt gives a white precipitate. The salt is likely to be a? Options:
  A) nitrate
  B) carbonate
  C) chloride
  D) sulphide
  Show Answer
  The correct answer is B .
• Question 1650: A burning candle produces water and Options:
  A) Carbon (II) oxide
  B) Carbon (IV) oxide
  C) Oxygen
  D) Hydrogen
  Show Answer
  The correct answer is B .