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 1: Which of the following is a example of a chemical change? Options:
  A) Dissoultion of salt in water
  B) Rusting of iron
  C) Melting of ice
  D) Separating a mixture by distillation
  Show Answer
  The correct answer is B .
• Question 2: A change in the temperature of a saturated solution disturbs the equilibrium between the Options:
  A) Undissolved solute and the solvent
  B) Dissolved solute and the solvent
  C) Dissolved solute and the undissolved solute
  D) Dissolved solute and the solution
  Show Answer
  The correct answer is C .
• Question 3:

  Which of the following represents the kind of bonding present in ammonium chloride?

  Options:
  A) ionic only
  B) covalent only
  C) ionic and dative covalent
  D) dative covalent
  Show Answer
  The correct answer is C .
• Question 4: When a bottle of Coca-Cola is opened, bubbles of evolve. The gas is? Options:
  A) hydrogen
  B) carbon monoxide
  C) carbon dioxide
  D) sulphur oxide
  E) chlorine
  Show Answer
  The correct answer is C .
• Question 5: Which of the following metals is purified commercially by electrolysis? Options:
  A) Zn
  B) Fe
  C) Sn
  D) Cu
  Show Answer
  The correct answer is D .
• Question 6: The property of concentrated H₂SO₄ that makes it suitable for preparing HNO₃ is its Options:
  A) boiling point
  B) density
  C) oxidizing properties
  D) dehydrating properties
  Show Answer
  The correct answer is C .
• Question 7: A common characteristics of copper and silver in their usage as coinage metals is that they Options:
  A) have high metallic lustre
  B) are not easily oxidized
  C) are easily oxidized
  D) are not easil reduced
  Show Answer
  The correct answer is B .
• Question 8:

  CO_(g) + H₂O_(g) → CO_2(g) + H_2(g)

  From the reaction above, calculate the standard enthalpies of formation of CO_2(g), H₂O_(g) and CO_(g) in kJ mol^-1 are -394, -242, and -110 respectively.

  Options:
  A) -262 kJ mol^-1
  B) -42 kJ mol^-1
  C) +42 kJ mol^-1
  D) +262 kJ mol^-1
  Show Answer
  The correct answer is B .
• Question 9:

  Which of the following alkaline metals react more quickly spontaneously with water?

  Options:
  A) Calcium
  B) Beryllium
  C) Magnesium
  D) Strontium
  Show Answer
  The correct answer is A .
• Question 10: The relative atomic mass of a naturally occurring lithium consisting of 90%$\frac{7}{3}$Li and 10%$\frac{6}{3}$Li is Options:
  A) 6.2
  B) 6.8
  C) 7.1
  D) 6.9
  Show Answer
  The correct answer is D .