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 531: An increase in the pressure exerted on gas at a constant temperature results in Options:
  A) a decrease in the number of effective collisions
  B) a decrease in volume
  C) an increase in the average intermolecular distance
  D) an increase in volume
  Show Answer
  The correct answer is B .
• Question 532:

  

  Z in diagram above represents

  Options:
  A) heat of reaction
  B) activation energy
  C) free energy
  D) entropy of reaction
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  The correct answer is A .
• Question 533:

  Which of the following alkaline metals react more quickly spontaneously with water?

  Options:
  A) Calcium
  B) Beryllium
  C) Magnesium
  D) Strontium
  Show Answer
  The correct answer is A .
• Question 534: In the extraction of iron, the waste gas from the furnace is a mixture of Options:
  A) PH₃ CO and CO₂
  B) CO and C
  C) N₂ CO and CO₂
  D) PH₃ and CO
  Show Answer
  The correct answer is A .
• Question 535:

  An element has an atomic number of 8 and a mass number of 16. How many neutrons does this element have?

  Options:
  A) 24
  B) 16
  C) 8
  D) 32
  Show Answer
  The correct answer is C .
• Question 536: Geometric isomerism can exist in Options:
  A) hex-3-ene
  B) hexane
  C) prop-l-ene
  D) 3-methyl but -l-ene
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  The correct answer is A .
• Question 537:

  The atomic weight of nitrogen is?

  Options:
  A) 10
  B) 12
  C) 14
  D) 16
  Show Answer
  The correct answer is C .
• Question 538: 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 539:

  Which functional group is present in alkanals?

  Options:
  A) Carbonyl group (C=O)
  B) Hydroxyl group (-OH)
  C) Alkyl group (-R)
  D) Carboxyl group (-COOH)
  Show Answer
  The correct answer is A .
• Question 540: 2SO_2(g) + O_2(g) ↔ 2SO_3(g). In the chemical reaction above, the substance that will increase the rate of production of sulphur (VI) oxide is Options:
  A) manganese (IV) oxide
  B) finely divided iron
  C) vanadium (V) oxide
  D) nickel
  Show Answer
  The correct answer is C .