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 2181:

  What is the maximum number of electrons that can occupy the second energy level (n=2)?

  Options:
  A) 2 electrons
  B) 18 electrons
  C) 8 electrons
  D) 32 electrons
  Show Answer
  The correct answer is C .
• Question 2182: A mixture of iodine and sulphur crystals can be separated by treatment with Options:
  A) water to filter off sulphur
  B) carbon (IV) suiphide to filter off iodine
  C) ethanoic acid to filter off sulphur
  D) methanol to filter off iodine
  Show Answer
  The correct answer is B .
• Question 2183:

  At 25^o and zymase as catalyst,

  C₆H₁₂₆ → 2C₂H₅OH + 2CO₂ + energy

  The reaction above represented by the equation above is useful in the production of

  Options:
  A) propanol
  B) butanol
  C) methanol
  D) ethanol
  Show Answer
  The correct answer is D .
• Question 2184: What weight of sodium hydroxide is required to make 500 cm³ of 0.2 M solution?(Na = 23, O = 16, H = 1) Options:
  A) 40 g
  B) 20 g
  C) 10 g
  D) 4 g
  E) 2 g
  Show Answer
  The correct answer is D .
• Question 2185: Which of the following metals is purified commercially by electrolysis? Options:
  A) Zn
  B) Fe
  C) Sn
  D) Cu
  Show Answer
  The correct answer is D .
• Question 2186: Which of the following properties is NOT peculiar to matter? Options:
  A) kinetic energy of particles increase from solid to gas
  B) Random motion of particles increases from liquid to gas
  C) Orderliness of particles increases from gas to liquid
  D) Random motion of particles increases from gas to solid
  Show Answer
  The correct answer is D .
• Question 2187:

  C₃H₅ - COH₃ =CH₂

  The IUPAC nomenclature of the structure above is

  Options:
  A) 3-methybut-3-ene
  B) 2-methylbut-1-ene
  C) 2-ethylprop-1-ene
  D) 2-methylbut-2-ene
  Show Answer
  The correct answer is B .
• Question 2188: The oxidation state of oxygen in tetraoxosulphate (VI) acid is Options:
  A) -4
  B) -2
  C) +4
  D) -8
  Show Answer
  The correct answer is B .
• Question 2189: Which of the following are the products of the reaction between CH₃COOH and CI₂ in sunlight? Options:
  A) CICH₂COOH + HCI
  B) CH₃COCI + HOCI
  C) CH₃COOCI + HCI
  D) CH₃COCI + HO₂
  Show Answer
  The correct answer is A .
• Question 2190: The products of the reaction between dilute sulphuric acid and sodium thiosulphate crystals are? Options:
  A) Na₂SO₄ + SO₂ + O₂ + H₂O
  B) Na₂SO₃ + SO₃ + O₂ + H₂O
  C) Na₂SO₄ + SO₂ + S + H₂O
  D) Na₂SO₄ + SO₃ + S + H₂O
  E) Na₂SO₄ + SO₂ + H₂O only
  Show Answer
  The correct answer is C .