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 751: How many isomers does pentane have? Options:
  A) 6
  B) 5
  C) 4
  D) 3
  Show Answer
  The correct answer is D .
• Question 752:

  The sulphide that is commonly used in coating electric fluorescent tubes is?

  Options:
  A) iron(ii)Sulphide
  B) tin(ii)sulphide
  C) Zinc Sulphide
  D) lead(iv) Sulphide
  Show Answer
  The correct answer is C .
• Question 753:

  The IUPAC nomenclature of the compound

  H${}_3$C - CH(CH${}_3$) - CH(CH${}_3$) - CH${}_2$ - CH${}_3$

  Options:
  A) 3,4- dimethylhexane
  B) 2,3- dimethyl pentane
  C) 2- ethyl hexane
  D) 2,3- dimethylhexane
  Show Answer
  The correct answer is B .
• Question 754: Which of the following equations represents an oxidizing action of sulphur dioxide? Options:
  A) SO₂ + 2HNO₂ → H₂SO₄ + 2NO₂ + heat
  B) 2SO₂ + 2H₂O + O₂ → 2H₂SO₄
  C) SO₂ + 2H₂O + CI₂ → H₂SO₄ + 2HCI
  D) SO₂ + 2H₂S → 3S + 2H₂O
  E) K₂Cr₂O₇ + H₂SO₄ + 3SO₂ → K₂SO₄ + Cr₂(SO₄)₃ + H₂O
  Show Answer
  The correct answer is D .
• Question 755: An element used in the production of matches is Options:
  A) nitrogen
  B) aluminium
  C) copper
  D) sulphur
  Show Answer
  The correct answer is D .
• Question 756: Geometric isomerism can exist in Options:
  A) hex-3-ene
  B) hexane
  C) prop-l-ene
  D) 3-methyl but -l-ene
  Show Answer
  The correct answer is A .
• Question 757: The arrangement of particles in crystal lattices can be studied using Options:
  A) X - rays
  B) γ - rays
  C) α - rays
  D) β - rays
  Show Answer
  The correct answer is A .
• Question 758:

  

  In the diagram above the gas Y could be

  Options:
  A) hydrogen chloride
  B) oxygen
  C) carbon (IV) oxide
  D) chlorine
  Show Answer
  The correct answer is A .
• Question 759:

  Which of the following pollutants will lead to the depletion of ozone layer?

  Options:
  A) chlorofluorocarbon
  B) carbon (ii) oxide
  C) hydrogen sulphide
  D) sulphur (iv) oxide
  Show Answer
  The correct answer is A .
• Question 760: Iron is often galvanized in order to Options:
  A) make it more malleable
  B) remove the impurities in it
  C) protect it against corrosion
  D) render it passive
  Show Answer
  The correct answer is C .