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 1391: In the purification of impure samples of ethyl ethanoate synthesized by esterification, concentrated sodium trioxocarbonate (IV) solution is used to remove Options:
  A) water
  B) basic impurities
  C) acidic impurities
  D) ethoxyethane
  Show Answer
  The correct answer is C .
• Question 1392:

  

  The arrangement above can be used for the collection of

  Options:
  A) sulphur (IV) oxide
  B) ammonia
  C) hydrogen chloride
  D) nitrogen
  Show Answer
  The correct answer is C .
• Question 1393: The product formed when propanol is heated over a copper catalyst in the absence of oxygen are Options:
  A) CH₃CH₂CHO and H₂
  B) CH₃CHO and CO₂
  C) CH₃CH₂COOH and H₂
  D) CH₃COOH and CO₂
  Show Answer
  The correct answer is D .
• Question 1394:

  

  In the diagram above, Y is a mixture of

  Options:
  A) calcium hydroxide and ammonium chloride
  B) calcuim hydroxide and sodium chloride
  C) sodium chloride and ammonuim trioxonitrate (V)
  D) sodium dioxonitrate (lll) and ammouium chloride
  Show Answer
  The correct answer is A .
• Question 1395: A major factor coonsidered in selecting a suitable method for preparing a simple salt is its Options:
  A) crystalline form
  B) melting point
  C) reactivity with dilute acids
  D) solubility in water
  Show Answer
  The correct answer is D .
• Question 1396: Which of these solutions will give a white precipitate with a solution of barium chloride acidified with hydrochloric acid? Options:
  A) Sodium trioxocarbonate (IV)
  B) Sodium tetraoxosulphate (IV)
  C) Sodium trioxosulphate (IV)
  D) Sodium sulphide
  Show Answer
  The correct answer is A .
• Question 1397: A liquid that will dissolve fat is Options:
  A) hydrochloric acid
  B) calcium hydrochloride
  C) kerosene
  D) water
  Show Answer
  The correct answer is C .
• Question 1398: The property used in the industrial preparation of nitrogen and oxygen from air is Options:
  A) rate of diffusion
  B) density
  C) boiling point
  D) solubility
  Show Answer
  The correct answer is C .
• Question 1399: The pollutants that are likely to be present in an industrial environment are? Options:
  A) H₂S,SO₂ and oxides of nitrogen
  B) NH₃, HCI and CO
  C) CO₂, NH₃ and H₂S
  D) dust, NO and CI₂
  Show Answer
  The correct answer is A .
• Question 1400: The enzymes responsible for converting sucrose into two simple isomeric sugars is Options:
  A) maltase
  B) amylase
  C) invertase
  D) lactase
  Show Answer
  The correct answer is C .