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 1861:

  (1/2)Zn²⁺_(aq) + e^- → (1/2) Zn_(s)

  In the reaction above, calculate the quantity of electricity required to discharge zinc.

  [F = 96 500 C mol^-1]

  Options:
  A) 0.965 * 10₄C
  B) 4.820 * 10₄C
  C) 9.650 * 10₄C
  D) 48.200 * 10₄C
  Show Answer
  The correct answer is C .
• Question 1862: Which of the following equations show that a reaction is in equilibrium?
  Options:
  A) ΔG < O
  B) ΔG = ΔH – TΔS
  C) ΔG > O
  D) ΔG = O
  Show Answer
  The correct answer is D .
• Question 1863: Which of the following compounds and elements would sublime on exposure to the atmosphere? Options:
  A) Ice
  B) Sulphur
  C) Phosphurous
  D) Iodine
  E) Potassium iodie
  Show Answer
  The correct answer is D .
• Question 1864: When a crystal was added to the clear solution of its salt, the crystal did not dissolve and the solution remained unchange. This showed that the solution was Options:
  A) supersaturated
  B) concentrated
  C) unsaturated
  D) saturated
  Show Answer
  The correct answer is D .
• Question 1865: What is the consequences of increasing pressure on the equilibrium reaction ZnO_(s) + H_2(g) Zn_(s) + H₂O_(I)? Options:
  A) The equilibrium is driven to the left
  B) The equilibrium is driven to the right
  C) There is no effect
  D) More ZnO is produced
  Show Answer
  The correct answer is C .
• Question 1866: The atom of an element X is represented as _z^yX. The basic chemical properties of X depends on the value of Options:
  A) Y
  B) Z
  C) Y - Z
  D) Z - Y
  Show Answer
  The correct answer is B .
• Question 1867:

  

  From the diagram above, an ideal can be represented by

  Options:
  A) M
  B) N
  C) K
  D) L
  Show Answer
  The correct answer is B .
• Question 1868:

  How many pi ($\pi$) bonds are there in an alkene with six carbon atoms?

  Options:
  A) 4
  B) 6
  C) 5
  D) 3
  Show Answer
  The correct answer is D .
• Question 1869: Which of the following ions require the largest quantity of electricity for discharge at an electrode? Options:
  A) 4.0 moles of Cl^-
  B) 3.0 moles of Na⁺
  C) 2.5 moles of Cu²⁺
  D) 2.0 moles of Al³⁺
  Show Answer
  The correct answer is C .
• Question 1870: Copper (II) tetraoxosulphate (IV) is widely used as a? Options:
  A) fertilizer
  B) fungicide
  C) disinfectant
  D) purifier
  Show Answer
  The correct answer is B .