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 791: Chlorination of water for town supply is carried out to Options:
  A) make the water colourless
  B) remove germs from the water
  C) make the water tastedful
  D) remove odour from the water
  Show Answer
  The correct answer is B .
• Question 792:

  When the end alkyl groups of ethyl ethanoate are interchanged, the compound formed is

  Options:
  A) propylmethanoate
  B) ethylpropanoate
  C) methyl ethanoate
  D) methyl propanoate
  Show Answer
  The correct answer is B .
• Question 793:

  What is the trend for ionization energy across a period in the periodic table?

  Options:
  A) Increases from left to right.
  B) Remains constant
  C) Varies randomly
  D) Decreases from left to right
  Show Answer
  The correct answer is A .
• Question 794: A metal M displaces zinc from zinc chloride solution. This shows that Options:
  A) M is more electronegative than zinc
  B) Zinc is above hydrogen in the series
  C) M is more electropositive than zinc
  D) Electrons flow from zinc to M
  Show Answer
  The correct answer is C .
• Question 795: An endothermic reaction is one during which heat is.....and can be represented by the symbol.... which of the following combinations can be used accurately to complete the above definition? Options:
  A) liberated, -$\mathrm{\Delta }$H
  B) liberated, +$\mathrm{\Delta }$H
  C) absorbed, -$\mathrm{\Delta }$H
  D) absorbed, +$\mathrm{\Delta }$H
  E) absorbed, +$\mathrm{\Delta }$G
  Show Answer
  The correct answer is D .
• Question 796: Which of the following tests would confirm-unequivocally that a solution X contain the sulphate ion if it gives with Options:
  A) silver nitrates solution, a white precipates insoluble in dilute HNO₃
  B) barium chloride solution, a white precipitate insoluble in dilute H₂SO₄
  C) barium chloride solution, a white precipitate insoluble in dilute HCl
  D) barium chloride solution a white precipitate soluble in dilute ammonia
  E) barium chloride solution a white precipitate insoluble in dilute HCl
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  The correct answer is C .
• Question 797: Reduction of alkanonoes with LialH₄ produces Options:
  A) primary alkanols
  B) secondary alkanols
  C) tertiary alkanols
  D) polyhydric alkanols
  Show Answer
  The correct answer is B .
• Question 798:

  

  Use the following option above to answer this question. Which of the following is the functional group of carboxylic acids?

  Options:
  A) A
  B) B
  C) C
  D) D
  E) E
  Show Answer
  The correct answer is D .
• Question 799:

  Aluminum 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 800: In the electrolysis of brine, the anode is Options:
  A) platinum
  B) copper
  C) zinc
  D) carbon
  Show Answer
  The correct answer is D .