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 61:

  How many alkoxyalkanes can be obtained from the molecular formula C${}_4$H${}_{10}$O?

  Options:
  A) 4
  B) 2
  C) 1
  D) 3
  Show Answer
  The correct answer is D .
• Question 62:

  Oxygen is absent in?

  Options:
  A) Kerosene
  B) Soil
  C) Glass
  D) Cement
  Show Answer
  The correct answer is A .
• Question 63:

  Addition of charcoal to the filter bed of sand during water treatment for township supply is to?

  Options:
  A) prevent goiter
  B) prevent tooth decay
  C) remove odour
  D) kill germs
  Show Answer
  The correct answer is C .
• Question 64: What volume of 0.5 MH₂SO₄ will exactly neutralize 20cm³ of 0.1 MNaOH Solution? Options:
  A) 2.0cm³
  B) 5.0cm³
  C) 6.8cm³
  D) 8.3cm³
  Show Answer
  The correct answer is A .
• Question 65: The radioisotope used in industrial radiography for the rapid checking of faults in welds and casting is Options:
  A) carbon-14
  B) phosphorus-32
  C) cobalt-60
  D) iodine-131
  Show Answer
  The correct answer is C .
• Question 66:

  If the quantity of oxygen occupying 2.76L container at a pressure of 0.825 atm and 300k is reduced by one-half, what is the pressure exerted by the remaining gas?

  Options:
  A) 1.650atm
  B) 0.825atm
  C) 0.413atm
  D) 0.275atm
  Show Answer
  The correct answer is A .
• Question 67: The constituent of air that acts as a diluent is Options:
  A) nitrogen
  B) carbon (IV) oxide
  C) noble gases
  D) oxygen
  Show Answer
  The correct answer is A .
• Question 68: On heating anhydrous iron (ll) sulphate, in addition to producing iron (iii) oxide, which of the following is produced? Options:
  A) SO₂ (g) + FeS (s)
  B) SO₃ (g) +FeS(s)
  C) SO₂ (g) + SO₃(g)
  D) SO₂ (g) + H₂S (g)
  E) SO₃(g) + H₂S(g)
  Show Answer
  The correct answer is C .
• Question 69: Diamond cannot be used Options:
  A) In making bicycle chains
  B) As abrasives
  C) In cutting glass and metals
  D) As dies for drawing wires
  Show Answer
  The correct answer is A .
• Question 70:

  I. It has a varied composition from one place to another.

  II. It constituents can be separated by physical means.

  III. It contains unreactive noble gases

  Which of the above shows that air is a mixture?

  Options:
  A) I and II only
  B) II and III only
  C) I and III only
  D) I, II and III
  Show Answer
  The correct answer is A .