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 1971: 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 1972:

  Which of the following statements is true for strong electrolytes?

  Options:
  A) They do not conduct electricity in the molten state
  B) They completely dissociate into ions in solution
  C) They are non-polar substances
  D) They partially dissociate into ions in solution
  Show Answer
  The correct answer is B .
• Question 1973:

  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 .
• Question 1974:

  An organic compound contains 69% carbon, 15.3% hydrogen and 30.7% oxygen. Calculate the the empirical formula [C=12, H = 1, O = 16]

  Options:
  A) C${}_4$H${}_{1}2$O
  B) C${}_3$H${}_9$O
  C) C${}_4$H${}_9$O
  D) C${}_3$H${}_8$O
  Show Answer
  The correct answer is D .
• Question 1975: During a titration experiment, 0.05 moles of carbon (lV) oxide is liberated. What is the volume of gas liberated? Options:
  A) 22.40 dm ³
  B) 11.20 dm ³
  C) 2.24 dm ³
  D) 1.12 dm ³
  Show Answer
  The correct answer is D .
• Question 1976:

  

  The IUPAC nomenclature for the compound above is

  Options:
  A) dimethlhexane
  B) 3,5 dimethylhexane
  C) 1.1 dmethyl, 3 methylpentane
  D) 2.4 dimethylhexane
  Show Answer
  The correct answer is D .
• Question 1977: Phosphorus burns in oxygen according to the equation P₄ + 50₂ → P₄O₁₀. How many litres of oxygen will be required at S.T.P for complete oxidation of 12.4g of phosphorus? [P = 31,O = 16 and molar volume of a gas at S.T.P = 22.4 litres] Options:
  A) 5. 20
  B) 11. 20
  C) 2. 24
  D) 20. 20
  E) 6. 20
  Show Answer
  The correct answer is B .
• Question 1978:

  Helium is used in observation of ballons because it is?

  Options:
  A) Light and combustible
  B) light and non-combustible
  C) heavy and combustible
  D) heavy and non-combustible
  Show Answer
  The correct answer is B .
• Question 1979:

  Calculate the mass of chlorine gas which occupies a volume of 1.12dm³ at s.t.p

  [Cl = 35.5, molar volume of gas at s.t.p = 22.4 dm³

  Options:
  A) 15.50 g
  B) 7.10 g
  C) 3.55 g
  D) 1.80 g
  Show Answer
  The correct answer is C .
• Question 1980: 12 g of solid protassium chlorate (KCIO) were added to 40 g of water and heated to dissolve all the solid. As the solution cools, crystals of potassium chlorate at 66 ^oC. The solubility of potassium chlorate at 66 ^oC is therefore Options:
  A) 66
  B) 33
  C) 10
  D) 20
  E) 30
  Show Answer
  The correct answer is E .