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 1751: 300 cm³ of gas has a pressure of 800 mmHg. If the pressure is reduced to 650 mmHg, find its volume Options:
  A) 243.75 cm³
  B) 369.23 cm³
  C) 738.46 cm³
  D) 1733.36 cm³
  Show Answer
  The correct answer is B .
• Question 1752: Atomicity of ozone is Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is C .
• Question 1753:

  ${}_{11}^{11}Na{+}_0^{1}n{\to }_{11}^{24}Na$

  The reaction above is an example of

  Options:
  A) nuclear fission
  B) nuclear fusion
  C) artificial transmutation
  D) beta decay
  Show Answer
  The correct answer is C .
• Question 1754: Lucas reagent is used to test for Options:
  A) alkanes
  B) alkanoic acids
  C) alkanols
  D) amines
  Show Answer
  The correct answer is C .
• Question 1755: An element, Z froms an anion whose formula is [Z(CN)₆]^y. If Z has an oxidation number of +2, what is the value of y? Options:
  A) - 2
  B) - 3
  C) - 4
  D) - 5
  Show Answer
  The correct answer is C .
• Question 1756: The property of chlorine which causes hydrogen chloride to be more ionic than the chlorine molecules is its Options:
  A) electrovalency
  B) electron affinity
  C) electropositivity
  D) electronegativity
  Show Answer
  The correct answer is D .
• Question 1757: A few drops of NaOH solution was added to an unknown salt forming a white precipitate which is insoluble in excess solution. The cation likely present is Options:
  A) Zn²⁺
  B) Pb²⁺
  C) Ca²⁺
  D) Al³⁺
  Show Answer
  The correct answer is C .
• Question 1758:

  Wrought iron is obtained by heating cast iron in a furnace with?

  Options:
  A) magnetite
  B) haematite
  C) carbon(ii)oxide
  D) calcium trioxosilicate(iv)
  Show Answer
  The correct answer is B .
• Question 1759: Ethyne is passed through a hot tube containing organo-nickel catalyst to produce Options:
  A) isoprene
  B) polythene
  C) ethanol
  D) benzene
  Show Answer
  The correct answer is D .
• Question 1760: C₃H_8(g) + 50_2(g) → 4H₂O + 3CO_2(g). Form the equation above the volume of oxygen at s.t.p. required to burn 50cm³ of propane is? Options:
  A) 250 cm³
  B) 150 cm³
  C) 100 cm ³
  D) 50 cm³
  Show Answer
  The correct answer is A .