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 1111: The enzyme used in the hydrolysis of starch to dextrin and maltose is Options:
  A) Zymase
  B) Sucrase
  C) Amylase
  D) Lactase
  Show Answer
  The correct answer is C .
• Question 1112:

  What number of moles of Cu ²⁺ will be deposited by 360 coulombs of electricity?

  [f = 96500 C mol ^-1]

  Options:
  A) 5.36 x 10 ^-4 mole
  B) 1. 87 x 10 10 ^-3 mole
  C) 9. 35 x 10 ^-4 mole
  D) 3. 73 x 10 ^-3
  Show Answer
  The correct answer is B .
• Question 1113: In the electrolytic extraction of cacium from calcium chloride, the cathode is Options:
  A) zinc
  B) graphite
  C) platinum
  D) iron
  Show Answer
  The correct answer is D .
• Question 1114:

  What happens to the position of equilibrium, if a reversible exothermic reaction is subjected to a decrease in temperature?

  Options:
  A) The position of equilibrium shifts to the left
  B) The position of equilibrium shifts to the right.
  C) The position of equilibrium remains unchanged
  D) The reaction stops
  Show Answer
  The correct answer is B .
• Question 1115: Commercial bleaching can be carried out using Options:
  A) sulphur (IV) oxide and ammonia
  B) hydrogen sulphide and chlorine
  C) chlorine and sulphur (IV) oxide
  D) ammonia and chlorine
  Show Answer
  The correct answer is C .
• Question 1116: The compounds CH₃CH₂CHO and CH₃COCH₃ can be distinguished from each other using Options:
  A) Dilute ammonia
  B) Benedict's solution
  C) Tollen's reagent
  D) Sodium hydroxide solution
  Show Answer
  The correct answer is C .
• Question 1117: When excess chlorine is mixed with ethene at room temperature, the product is Options:
  A) 1,2 - dichloroethane
  B) 1,2 - dichloroethene
  C) 1,1 - dichloroethane
  D) 1, 1 - dichloroethene
  Show Answer
  The correct answer is A .
• Question 1118: How many electrons are in the L shell of ³¹₁₅P? Options:
  A) 5
  B) 8
  C) 18
  D) 2
  Show Answer
  The correct answer is B .
• Question 1119: In a neutralization reaction involving HCI and NaOH using litmus as indicator, the colour at the end point is Options:
  A) Blue
  B) Red
  C) Orange
  D) Purple
  Show Answer
  The correct answer is C .
• Question 1120:

  The shape of ammonia molecule is?

  Options:
  A) Trigonal planar
  B) Octahedral
  C) Square planar
  D) Tetrahedral
  Show Answer
  The correct answer is A .