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 1781: An isomer of C₅H₁₂ is Options:
  A) 2–ethyl butane
  B) butane
  C) 2–methyl butane
  D) 2–methyl propane
  Show Answer
  The correct answer is C .
• Question 1782:

  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 1783:

  

  The compound above is the product of the oxidation of

  Options:
  A) 2-methlbutan-2-ol
  B) 2-methylbutan -1- ol
  C) 2, 3-dimethylprop 1-ol
  D) Pentan -2- ol
  Show Answer
  The correct answer is B .
• Question 1784: Aluminium containers are frequently used to transport trioxonitrate (V) acid because aluminium Options:
  A) has a silvery-white appearance
  B) has a low density
  C) does not react with the acid
  D) does not corrode
  Show Answer
  The correct answer is C .
• Question 1785:

  What is the main source of carbon monoxide (CO) in urban areas?

  Options:
  A) Volcanic eruptions
  B) Vehicle emissions
  C) Forest fires
  D) Industrial processes
  Show Answer
  The correct answer is B .
• Question 1786: Which of the following represents saponification? Options:
  A) Reaction of carboxylic acids with sodium hydroxide
  B) Reaction of alkanoates with acid
  C) Reaction of alkanoates with alcohols
  D) Reaction of alkanoates with sodium hydroxide
  Show Answer
  The correct answer is D .
• Question 1787: A gas that can behave as a reducing agent towards chlorine and as an oxidizing agent toward hydrogen sulphide is Options:
  A) O₂
  B) NO
  C) SO₂
  D) NH₃
  E) CO₂
  Show Answer
  The correct answer is C .
• Question 1788:

  Which of the following compounds will form a solution if exposed to air?

  Options:
  A) Na₂CO₃.10H₂O
  B) NaNO₃
  C) CuSO₄
  D) CaCl₂
  E) NaSO₄.10H₂O
  Show Answer
  The correct answer is D .
• Question 1789:

  

  Use the above option to answer this question. The dehydration of ammonium salt of alkanoic acids produces a compound with the general formula

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .
• Question 1790: Which of the following processes NOT lead to a chemical change? Options:
  A) Strirring iron in sulphur (IV) acid
  B) Stirring sodium carbonate in water
  C) Stirring glucose in concentrated sulphur (IV) acid
  D) Mixing sulphur (IV) acid with potassium carbonate
  E) Titrating an acid against base
  Show Answer
  The correct answer is B .