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 521: The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as; Options:
  A) saponification
  B) dehydration
  C) esterification
  D) hydrolysis
  E) hydration
  Show Answer
  The correct answer is C .
• Question 522: In the reaction M + N P;∆H = + QKJ. Which of the following would increase the concentration of the product? Options:
  A) Decreaseing the concentration of N
  B) Increasing the concentration of P
  C) Adding a suitable catalyst
  D) Decreasing the temperature
  E) Increasing the temperature
  Show Answer
  The correct answer is E .
• Question 523: The Arrhenius equation expresses the relationship between the speed of a reaction and its Options:
  A) Molecular collision
  B) Heat of reaction
  C) Catalyst
  D) Activation energy
  Show Answer
  The correct answer is A .
• Question 524:

  A compound contains 40.0% carbon 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180, find the molecular formula.

  [H = 1, C = 12, O = 16]

  Options:
  A) CH₂O
  B) C₃H₆O₃
  C) C₆H₁₂O₆
  D) C₆H₁₂O₃
  Show Answer
  The correct answer is C .
• Question 525:

  How many moles of limestone will be required to produce 5.6g of CaO?

  [Ca = 40, C = 12, O= 16]

  Options:
  A) 0.20 mol
  B) 0.10 mol
  C) 1.12 mol
  D) 0.56 mol
  Show Answer
  The correct answer is B .
• Question 526:

  

  Use the table above to answer this question .The least reactive element is

  Options:
  A) W
  B) X
  C) Y
  D) Z
  Show Answer
  The correct answer is D .
• Question 527: When large hydrocarbon molecules are heated at high temperature in the presence of a catalyst to give smaller molecules, the process is known as Options:
  A) disintegration
  B) polymerization
  C) cracking
  D) degradation
  E) distillation
  Show Answer
  The correct answer is C .
• Question 528: An example of an acidic oxide is Options:
  A) NO
  B) CO
  C) SO₂
  D) CuO
  Show Answer
  The correct answer is C .
• Question 529: Which of the following ions is acidic? Options:
  A) K⁺
  B) KNO₃^-
  C) S^2-
  D) H₃O⁺
  Show Answer
  The correct answer is B .
• Question 530: Which of the following alkanes has the highest boiling point? Options:
  A) Pentane
  B) Ethane
  C) Propane
  D) Methane
  Show Answer
  The correct answer is A .