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 181:

  Which of the following methods is commonly used to remove suspended impurities from water?

  Options:
  A) Fluoridation
  B) Chlorination
  C) Filtration
  D) Distillation
  Show Answer
  The correct answer is C .
• Question 182:

  2Na ₂ O _2(s) + 2H ₂ O ₂₍₁₎ → 4 NaOH_(s) +O_2(s)

  The substance that is oxidized in the reaction above is

  Options:
  A) 2NaO_2(s)
  B) NaOH(aq)
  C) H₂O₍₁₎
  D) O_2(g)
  Show Answer
  The correct answer is A .
• Question 183:

  Give the common name for the following compound (CH${}_3$)${}_2$ CH CH${}_2$ -Br

  Options:
  A) Isobutyl bromide
  B) Methyl bromide
  C) propyl bromide
  D) Butyl bromide
  Show Answer
  The correct answer is A .
• Question 184: When ΔH is negative, a reaction is said to be Options:
  A) endothermic
  B) exothermic
  C) reversible
  D) ionic
  Show Answer
  The correct answer is B .
• Question 185: Which of the following is a measure of the average kinetic energy of the molecules of a substance? Options:
  A) Volume
  B) Mass
  C) Pressure
  D) Temperature
  Show Answer
  The correct answer is D .
• Question 186: The atom of an element X is represented as ${}_z^{y}X$. The basic chemical properties of X depend on the value of Options:
  A) Y
  B) Z
  C) Y - Z
  D) Z - Y
  Show Answer
  The correct answer is B .
• Question 187: 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 188:

  The metal used to recover copper from a solution of copper sulphateis?

  Options:
  A) Na
  B) Ag
  C) Hg
  D) Fe
  Show Answer
  The correct answer is D .
• Question 189:

  When chlorine water is exposed to bright sunlight, the following products are formed

  Options:
  A) HCl${}_{(aq)}$ and Cl${}_2$
  B) HOCl${}_{(aq)}$ and Cl${}_2$
  C) HCl${}_{(aq)}$ and O${}_2$
  D) HOCl${}_{(aq)}$ and O${}_2$
  Show Answer
  The correct answer is C .
• Question 190:

  Hydrocarbons which will react with Tollen's reagent conform to the general formula

  Options:
  A) C${}_n$H${}_{2n}$
  B) C${}_n$H${}_{2n+2}$
  C) C${}_n$H${}_{2n-2}$
  D) C${}_n$H${}_{2n+1}$OH
  Show Answer
  The correct answer is C .