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 1721: The oxidation state of oxygen in tetraoxosulphate(IV) acid is Options:
  A) -4
  B) +4
  C) -2
  D) +2
  Show Answer
  The correct answer is C .
• Question 1722: The fraction of crude oil used as jet fuel is Options:
  A) refinery gas
  B) diesel oil
  C) kerosine
  D) gasoline
  Show Answer
  The correct answer is C .
• Question 1723:

  By what amount must the temperature of 200cm${}^3$ of Nitrogen at 27°C be increased to double the pressure if the final volume is 150cm${}^3$ (Assume ideality)

  Options:
  A) 150°C
  B) 177°C
  C) 75°C
  D) 120°C
  Show Answer
  The correct answer is B .
• Question 1724: If the rate of diffusion of oxygen gas is taken as 1, what will be rated of diffusion of methane whose relative molar mass is 16? Options:
  A) 2.0
  B) 1.8
  C) 1.4
  D) 1.0
  E) 0.5
  Show Answer
  The correct answer is C .
• Question 1725: During the electrolysis of a salt of a metal M, a current of 0.5 A flows from for 32 minutes 10 seconds and deposits 0.325 g of M, What is the charge of the metal ion?(M = 65, If = 96,500 C per mole of electron) Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is B .
• Question 1726: A cycloalkane with the molecular formula C₅H₁₀ has ? Options:
  A) one isomer
  B) two isomers
  C) three isomers
  D) four isomers
  Show Answer
  The correct answer is C .
• Question 1727: Which of the following statements is TRUE of the complete hydrolysis of a glycerine by sodium hygroxide? Options:
  A) 3 moles ofNaOH are required for each mole of glyceride
  B) 3 moles of glycerol are produced
  C) Only one mole of soap is formed
  D) concentrated H₂SO₄ is essential for the completion of the reaction
  Show Answer
  The correct answer is A .
• Question 1728: The order in which a mixture of sand, ammonium chloride and sodium chloride can be separated is Options:
  A) dissolution → dryness → filtration → evaporation
  B) filtration → sublimation → evaporation → dryness
  C) sublimation → dissolution → filtration → evaporation
  D) dissolution → filtration → sublimation → evaporation
  Show Answer
  The correct answer is C .
• Question 1729:

  

  The oxidation of the compound above produces

  Options:
  A) 2-butanone
  B) 2-butanal
  C) 3-butanal
  D) 3-butanone
  Show Answer
  The correct answer is A .
• Question 1730:

  

  Which of the following compounds will take up the molecules of bromine?

  Options:
  A) l
  B) ll
  C) lll
  D) l and ll
  E) l and lll
  Show Answer
  The correct answer is B .