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 901: The air around a petroleum refinery is most likely to contain? Options:
  A) CO₂, SO₃ and N₂O
  B) CO₂, CO and N₂O
  C) SO₂, CO and NO₂
  D) PH₃ H₂O and CO₂
  Show Answer
  The correct answer is C .
• Question 902:

  Benzene can be converted to its derivative toluene by the addition of a methyl group. The reaction is an example of

  Options:
  A) Nucleophilic substitution
  B) Elimination reaction
  C) Electrophilic substitution
  D) Addition reaction
  Show Answer
  The correct answer is C .
• Question 903:

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. At room temperature (300 K)

  Options:
  A) Y is twice as soluble as X
  B) X is twice as soluble as Y
  C) X and Y are soluble to the same extent
  D) X is three times as soluble as Y
  E) Y is three times as soluble as X
  Show Answer
  The correct answer is A .
• Question 904: The air around smelting industries is likely to contain Options:
  A) H₂S, CO and N₂
  B) CO₂, SO₃ and H₂
  C) H₂, SO₂ and CO₂
  D) SO₂, N₂ and CO₂
  Show Answer
  The correct answer is C .
• Question 905: In an electrochemical cell, polarization is caused by Options:
  A) chlorine
  B) oxygen
  C) tetaoxsulphate (Vl) acid
  D) hydrogen
  Show Answer
  The correct answer is D .
• Question 906: A metallic oxide which reacts with both HCl and NaOH to give salt and water only can be classified as? Options:
  A) an acidic oxide
  B) a basic oxide
  C) a neutral oxide
  D) an amphoteric oxide
  Show Answer
  The correct answer is D .
• Question 907:

  

  Which of the following compounds is a secondary alkanol?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 908: Aluminium hydroxide is used in the dyeing industry as a Options:
  A) dye
  B) dispersant
  C) salt
  D) mordant
  Show Answer
  The correct answer is D .
• Question 909: Which of the following metals is the least reactive? Options:
  A) Pb
  B) Sn
  C) Hg
  D) Au
  Show Answer
  The correct answer is D .
• Question 910: Alkanoates are formed by the reaction of alkanoic acid with? Options:
  A) Alkyl halides
  B) alkanols
  C) ethers
  D) sodium
  Show Answer
  The correct answer is B .