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 621: Which of the following classes of organic compounds undergoes rapid oxidation with bromine water? Options:
  A) alcohols
  B) alkenes
  C) carboxylic acids
  D) esters
  E) alkanes
  Show Answer
  The correct answer is B .
• Question 622: In the industrial production of H₂ is removed by (solution) Options:
  A) washing under pressure
  B) drying over phosphorus (V) oxide
  C) passing the mixture to the limewater
  D) using ammonical copper (I) chlorine
  Show Answer
  The correct answer is A .
• Question 623:

  What happens to the position of equilibrium, if a reversible exothermic reaction is subjected to a decrease in temperature?

  Options:
  A) The position of equilibrium shifts to the left
  B) The position of equilibrium shifts to the right.
  C) The position of equilibrium remains unchanged
  D) The reaction stops
  Show Answer
  The correct answer is B .
• Question 624: In the extraction of sodium from fused sodium chloride, the anode is made of platinum because Options:
  A) sodium is formed at the anode
  B) chlorine is formed at the anode
  C) sodium does not react with platinum
  D) chlorine does not react with platinum
  Show Answer
  The correct answer is C .
• Question 625: A polymerization reaction is one in which? Options:
  A) small molecules form giant molecules
  B) atoms form molecules
  C) giant molecules form small molecules
  D) molecules form volatile compounds
  E) a molecule rearranges itself
  Show Answer
  The correct answer is A .
• Question 626: CaO_s + H₂O_(l) → Ca(OH)_2(s) ΔH -65 kj. The process represented by the above equation is known as? Options:
  A) dissolution
  B) slaking
  C) liming
  D) mortaring
  Show Answer
  The correct answer is B .
• Question 627: The leachate of a certain plant ash is used in local soap making because it contains Options:
  A) sodium chloride and potassium hydroxide
  B) sodium hydroxide
  C) potassium hydroxide
  D) soluble carbonates and hydrogen carbonates
  Show Answer
  The correct answer is B .
• Question 628:

  How many grams of methylacetylene (propyne) CH₃ - C Ξ CH will completely discharge the colour of 8g of bromine?

  (Br = 80, C = 12, H = 1)

  Options:
  A) 0.5
  B) 1.0
  C) 2.0
  D) 3.0
  E) 4.0
  Show Answer
  The correct answer is B .
• Question 629: The reaction of an alkene with hydrogen in the presence of catalyst is Options:
  A) a substitution reaction
  B) an oxidation reaction
  C) a nucleophilic reaction
  D) an addition reaction
  Show Answer
  The correct answer is D .
• Question 630: Which of the following will shift to the left from dilute tetraoxosulphate (VI) acid? Options:
  A) Lead
  B) Magnesium
  C) Cpper
  D) Gold
  Show Answer
  The correct answer is B .