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 421: The solubility curve shows the variation of solute concentration with Options:
  A) volume
  B) temperature
  C) vapour
  D) pressure
  E) weight
  Show Answer
  The correct answer is A .
• Question 422: To make coloured glasses, small quantities of oxides of metals which form coloured silicates are often added to the reaction mixture consisting of Na₂CO₃ and SiO₂. Such a metals is a?. Options:
  A) pottasium
  B) barium
  C) zinc
  D) copper
  Show Answer
  The correct answer is D .
• Question 423:

  What is the atomic number of aluminium?

  Options:
  A) 13
  B) 26
  C) 14
  D) 12
  Show Answer
  The correct answer is A .
• Question 424: The salt that will form a precipitate soluble in excess ammonia solution is Options:
  A) Ca(NO₃)₂
  B) Cu(NO₃₎₂
  C) Mg(NO₃₎₂
  D) Al(NO₃₎₃
  Show Answer
  The correct answer is B .
• Question 425:

  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 426:

  Duralumin consists of aluminum, copper?

  Options:
  A) Zinc and Gold
  B) Lead and Manganese
  C) Nickel and Silver
  D) Manganese and Magnesium
  Show Answer
  The correct answer is D .
• Question 427: The metal whose ore can be concentrated by passing it through a magnetic separator is Options:
  A) Zn
  B) Sn
  C) Cn
  D) Ca
  Show Answer
  The correct answer is B .
• Question 428:

  A chemical widely used as a fertilizer is?

  Options:
  A) galena
  B) bauxite
  C) emerald
  D) nitrochalk
  Show Answer
  The correct answer is D .
• Question 429: When few drops of concentrated trioxonitrate(V) acid is added to an unknown sample and wanned an intense yellow colouration is observed. The likely functional group present in the sample is Options:
  A) NH₃—C—C=O
  B) CHO
  C) CO
  D) CNH₂
  Show Answer
  The correct answer is A .
• Question 430: How many faraday of electricity is required to produce 0.25 mole of copper? Options:
  A) 1.00F
  B) 0.01F
  C) 0.05F
  D) 0.50F
  Show Answer
  The correct answer is D .