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 611:

  

  In the experiment above, X is a mixture of nitrogen, carbon (IV) oxide and

  Options:
  A) water
  B) impurities
  C) inert gas
  D) oxygen
  Show Answer
  The correct answer is C .
• Question 612:

  

  Which of the structural forms above is ethanoic acid is

  Options:
  A) A
  B) B
  C) C
  D) D
  E) E
  Show Answer
  The correct answer is E .
• Question 613: Bleaching powder, CaOCI₂, H₂O, deteriorates on exposure to air because Options:
  A) it loses its water of crystallization
  B) atmospheric nitrogen displaces chlorine from it
  C) carbon (IV) oxide of the atmosphere displaceschlorine from it
  D) bleaching agents should be stored in solution
  Show Answer
  The correct answer is C .
• Question 614:

  A sample of a substance containing only C and H burns in excess O₂ to yield 4.4g of CO₂

  And 2.7 g of H₂O. The empirical formula of a substance is?(C = 12, O = 16, H = 1)

  Options:
  A) CH₃
  B) CH₂
  C) CH₄
  D) C₂H₂₄
  Show Answer
  The correct answer is A .
• Question 615: Which of the following is a neutralization reaction? Addition of Options:
  A) nitric acid to hydrochloric acid
  B) nitric acid to sulphuric acid
  C) nitric acid to distilled water
  D) nitric acid to sodium hydroxide
  E) sodium chloride to distilled water
  Show Answer
  The correct answer is D .
• Question 616:

  

  Use the table above to answer this question. The element that is likely to participate in covalent rather than ionic bonding is

  Options:
  A) Z
  B) Y
  C) X
  D) W
  Show Answer
  The correct answer is C .
• Question 617:

  The process or act of extracting a metal from its ore and refining it is called?

  Options:
  A) Extraction
  B) Metal mining
  C) Mettallurgy
  D) Prospecting
  Show Answer
  The correct answer is C .
• Question 618:

  2Na ₂ O _2(s) + 2H ₂ O ₂₍₁₎ → 4 NaOH_(s) +O_2(s)

  The substance that is oxidized in the reaction above is

  Options:
  A) 2NaO_2(s)
  B) NaOH(aq)
  C) H₂O₍₁₎
  D) O_2(g)
  Show Answer
  The correct answer is A .
• Question 619: The energy value of petrol can be determined by Options:
  A) Bomb calorimeter
  B) Catalytic cracker
  C) Fractionating column
  D) Thermometer
  Show Answer
  The correct answer is C .
• Question 620:

  0.0075 mole of calcium trioxocarbonate (IV) is added to 0.015 mole of a solution of hydrochloric acid. The volume of gas evolved at s.t.p is

  [Molar volume of a gas at s.t.p = 22.4 dm³]

  Options:
  A) 224cm³
  B) 168cm³
  C) 112cm³
  D) 100cm³
  Show Answer
  The correct answer is B .