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 41: The leachate of a certain ash is used in local soap because it contain Options:
  A) sodium chloride and potassium hydroxide
  B) sodium hydroxide
  C) potassium hydroxide
  D) soluble carbonates and hydrogen carbonate
  Show Answer
  The correct answer is B .
• Question 42:

  Which of the following is an example of a chemical change?

  Options:
  A) dissolution 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 43:

  Which of the following statements is true regarding the melting and boiling points of pure substances?

  Options:
  A) The boiling point is always higher than the melting point
  B) The melting point is always higher than the boiling point
  C) The melting and boiling points are always the same for all substances
  D) The melting and boiling points can vary depending on the substance
  Show Answer
  The correct answer is D .
• Question 44: Which of the following pairs has compounds that are isomers? Options:
  A) Propanal and propanone
  B) Ethanoic acid and ethylmethanoate
  C) Ethanoic acid and ethane-1, 2-diol
  D) 2-methylbutane and 2, 2-dimethylbutane
  Show Answer
  The correct answer is D .
• Question 45: Ethanoic acid is Options:
  A) tribasic
  B) unionizeable
  C) monobasic
  D) dibasic
  Show Answer
  The correct answer is C .
• Question 46: Which of the following compounds will undergo polymerization reaction? Options:
  A) C₂H₄
  B) C₂H₅COOH
  C) C₂H₆
  D) C₂H₅OH
  Show Answer
  The correct answer is A .
• Question 47:

  200cm${}^3$ of 0.50mol/dm${}^3$ solution of calcium hydrogen trioxocarbonate (IV) is heated. The maximum weight of solid precipitated is

  Options:
  A) 10g
  B) 25g
  C) 20g
  D) 15g
  Show Answer
  The correct answer is A .
• Question 48: In the industrial production of hydrogen from natural gas, carbon (IV) oxide produced along with the hydrogen is removed by? Options:
  A) washing under pressure
  B) passing the mixture into lime water
  C) using ammoniacal copper (l) chloride
  D) drying over phoshorus (V) oxide
  Show Answer
  The correct answer is C .
• Question 49: When water boilers are used for long period of time, the solid substances left behind as scale are Options:
  A) magnesium trioxosilicate (IV) and rust
  B) magnesium trioxosilicate (IV) and calcium tetraoxosulphate (VI)
  C) clay and magnesium troxosulphate (IV)
  D) clay and rust
  Show Answer
  The correct answer is A .
• Question 50:

  2-methylprop-1-ene is a structuralisomer of?

  Options:
  A) But-1-yne
  B) 2-methyl But-1-ene
  C) 3-methyl prop-1-yne
  D) But-2-ene
  Show Answer
  The correct answer is D .