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 one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series? Options:
  A) Copper
  B) Iron
  C) Lead
  D) Potassium
  E) Zinc
  Show Answer
  The correct answer is D .
• Question 2:

  On which of the following is the solubility of a gaseous substance dependent? 

  I. Nature of solvent 

  II. Nature of solute 

  III. Temperature 

  IV. Pressure

  Options:
  A) I, II, III and IV
  B) I and II only
  C) II only
  D) I, III and IV only
  Show Answer
  The correct answer is D .
• Question 3: A compound contains 40.0% C, 6.7% H 53.3% O. If the molecular mass of the compound is 180, its molecular formula is [C =12, H =1,O] Options:
  A) CH₂O
  B) C₃H₆O₃
  C) C₆H₆O₃
  D) C₆H₁₂O₆
  Show Answer
  The correct answer is D .
• Question 4:

  Which of the following best represent solid gas mixture?

  Options:
  A) milk
  B) kerosene
  C) soil
  D) smoke
  Show Answer
  The correct answer is D .
• Question 5: $PC{l}_{5(g)}\to PC{l}_{3(g)}+C{l}_{2(g)}$
  In the reaction above, an increase in pressure will Options:
  A) decelerate the reaction
  B) Increase the yield of $PC{l}_3$
  C) increase the yield of $PC{l}_5$
  D) accelerate the reaction
  Show Answer
  The correct answer is C .
• Question 6:

  

  In the diagram above, the mixture of the solids P and Q can be separated by

  Options:
  A) distillation
  B) fractional distillation
  C) crystallization
  D) fractional crystallization
  Show Answer
  The correct answer is C .
• Question 7: Oxygen-demanding waste are considered to be a water pollutant because they? Options:
  A) deplete oxygen which is necessary for the survival of aquatic organism
  B) increase oxygen which is necessary for survival of aquatic organism
  C) increase other gaseous substances which are necessary for the survival of aquatic organisms
  D) deplete other gaseous species which is necessary for the survival of aquatic organisms
  Show Answer
  The correct answer is A .
• Question 8:

  What happens when alkanoic acids react with alcohols in the presence of an acid catalyst?

  Options:
  A) Saponification
  B) Esterification
  C) Polymerization
  D) Hydrolysis
  Show Answer
  The correct answer is B .
• Question 9: When at equilibrium, which of the reactions below will shift to the right if the pressure is increased and the temperature is kept constant? Options:
  A) 2SO_3(g) ↔ 2SO_2(g) + O_2(g)
  B) 2CO_2(g) ↔ 2CO_(g) + O_2(g)
  C) 2H_2(g) + O_2(g) ↔ 2H₂O_(g)
  D) 2NO_(g) ↔ N_2(g) + O_2(g)
  Show Answer
  The correct answer is C .
• Question 10:

  

  2HCI_(ag) + CaCO_{3(s) → CaCl2(s)} + CO _2(g) +H₂O₍₁₎

  From the reaction above, which of the curves in the diagram represents the production of carbon (IV) oxide as dilute HCI is added?

  Options:
  A) L
  B) M
  C) N
  D) P
  Show Answer
  The correct answer is B .