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 1421: 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 1422:

  

  The compound above exhibits

  Options:
  A) Geometric isomerism
  B) Positional isomerism
  C) Structural isomerism
  D) Optical isomerism
  Show Answer
  The correct answer is D .
• Question 1423:

  C_(s) + H₂O_(g) → H_2(g) + CO_2(g)

  ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is

  Options:
  A) not feasible
  B) at equilibrium
  C) feasible
  D) exothermic
  Show Answer
  The correct answer is C .
• Question 1424: Which of the following fraction is used as raw material for the cracking process? Options:
  A) kerosine
  B) lubricating oil
  C) bitumen
  D) diesel oils
  Show Answer
  The correct answer is D .
• Question 1425: Bleaching powder, CaOCI₂, H₂O, deteriorates on exposure to air because Options:
  A) it loses its water of crystallization
  B) atmospheric nitrogen displaces chlorine from it
  C) carbon (IV) oxide of the atmosphere displaceschlorine from it
  D) bleaching agents should be stored in solution
  Show Answer
  The correct answer is C .
• Question 1426:

  8g CH₄ occupies 11.2 dm³ at s.t.p. What volume would 22 g of CH₃CH₃ occupy under the same condition?

  (C = 12, H = 1)

  Options:
  A) 3.7 dm³
  B) 11.2 dm³
  C) 22.4 dm³
  D) 33.6 dm³
  Show Answer
  The correct answer is B .
• Question 1427:

  If a solution contains 4.9g of tetraoxosulphate (VI) acid, calculate the amount of copper (II) oxide that will react with it

  [Cu = 64, O = 16, S = 32, H = 1]

  Options:
  A) 0.8g
  B) 4.0g
  C) 40.0g
  D) 80.0g
  Show Answer
  The correct answer is B .
• Question 1428: 25cm³ of a 0.2 mol dm³ solution of Na₂CO₃ requires 20 cm³ of a solution of HCl for neutralization. The concentration of the HCl solution is Options:
  A) 0.5 mol dm³
  B) 0.6 mol dm³
  C) 0.2 mol dm³
  D) 0.4 mol dm³
  Show Answer
  The correct answer is A .
• Question 1429: Three drops of a 1.0 mol dm^-3 solution of NaOH are added to 20 cm³ of a solution of pH 8.4. The pH of the resulting solution will be Options:
  A) Close to that of pure water
  B) Unaltered
  C) Greater than 8.4
  D) Less than 8.4
  Show Answer
  The correct answer is C .
• Question 1430:

  What is the percentage by mass of oxygen in Al₂(SO₄)₃. 2H₂O?

  [Al = 27, S = 32, H = 1, O = 16]

  Options:
  A) 14.29%
  B) 25.39%
  C) 50.79%
  D) 59.25%
  Show Answer
  The correct answer is D .