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 2021: In the laboratory preparation of oxygen, dried oxygen is usually collected over Options:
  A) hydrochloric acid
  B) mercury
  C) calcium chloride
  D) tetraoxosulphate (VI) acid
  Show Answer
  The correct answer is B .
• Question 2022: The solubility in moles per dm³ of 20g of CuSO₄ dissolve in 100 of water at 180°C is?(Cu = 63.5, S = 32, O = 16) Options:
  A) 0.13
  B) 0.25
  C) 1.25
  D) 2.00
  Show Answer
  The correct answer is C .
• Question 2023: The function of zinc electrode in a galvanic cells is that it Options:
  A) undergoes reduction
  B) serves as the positive electrode
  C) production electons
  D) uses up electrons
  Show Answer
  The correct answer is C .
• Question 2024: Sodium hydrogen should be stored in properly closed containers because it? Options:
  A) readily asborbs water vapour to air
  B) is easily oxidize by atmospheric oxygen
  C) turns golden yellow when exposed to light
  D) melts at a low temperature
  Show Answer
  The correct answer is A .
• Question 2025: The product of the electrolysis of dilute sodium hydroxide using platinum electrodes are Options:
  A) Hydrogen and oxygen gases
  B) Water and hydrogen gas
  C) Water and sodium metal
  D) Sodium metal and oxygen gas
  Show Answer
  The correct answer is A .
• Question 2026:

  Which of the following pairs of substances will react further with oxygen to form a higher oxide?

  Options:
  A) CO${}_2$ and H${}_2$O
  B) NO and H${}_2$O
  C) CO and CO${}_2$
  D) SO${}_2$ and NO
  Show Answer
  The correct answer is D .
• Question 2027:

  

  Use the graph above to answer this question.How long does it take all the solid to melt?`

  Options:
  A) 2.5 mins
  B) 6.0 mins
  C) 1.0 min
  D) 3.0 mins
  Show Answer
  The correct answer is A .
• Question 2028: Which of the following acts as both a reducing and an oxidizing agent? Options:
  A) H₂
  B) SO₂
  C) H₂S
  D) CO₂
  Show Answer
  The correct answer is B .
• Question 2029: Which of these reagents can confirm the presence of a triple bond? Options:
  A) Hypochlorous acid
  B) Bromine water
  C) Acidified KMnO4
  D) Copper I chloride
  Show Answer
  The correct answer is D .
• Question 2030: Which of the following compounds will undergo polymerization reaction? Options:
  A) C₂H₄
  B) C₂H₅COOH
  C) C₂H₆
  D) C₂H₅OH
  Show Answer
  The correct answer is A .