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 591:

  

  The diagram above shows the reaction path of an exothermic reaction. The heat of reaction is represented by

  Options:
  A) l
  B) ll
  C) lll
  D) lV
  Show Answer
  The correct answer is D .
• Question 592: 2MnO^-₄ + 10Cl^- + 16H⁺ → 2Mn²⁺ + 5Cl₂ + 8H₂O. Which of the substances serves as an oxidizing agent? Options:
  A) Mn²⁺
  B) Cl^-
  C) H₂O
  D) MnO^-₄
  E) Cl₂
  Show Answer
  The correct answer is D .
• Question 593:

  

  The curve depicts titration between

  Options:
  A) Strong acid and strong base
  B) Strong acid and weak base
  C) Weak acid and weak base
  D) Weak acid and strong base
  Show Answer
  The correct answer is C .
• Question 594: An increase in temperature causes an increase in pressure of a gas in a fixed volume due to an increase in the? Options:
  A) number of molecules of the gas
  B) density of the gas molecules
  C) number of collisions between the gas molecules
  D) number of collisions between the gas molecules and the walls of the container
  Show Answer
  The correct answer is D .
• Question 595: Addition of dilute hydrochloride acid to an aqueous solution of a crystalline salt yield a yellow precipitate and a gas which turned dichromate paper green. The crystalline salt was probably? Options:
  A) Na₂SO₄
  B) Na₂S
  C) Na₂S₂O₃.5H₂O
  D) Na₂CO₃
  E) NaHCO₃
  Show Answer
  The correct answer is C .
• Question 596:

  What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

  [H = 1, O = 16]

  Options:
  A) 36.0g
  B) 8.0g
  C) 72.0g
  D) 16.0g
  Show Answer
  The correct answer is C .
• Question 597:

  A substance that is used as a ripening agent for fruits is

  Options:
  A) ethene
  B) propane
  C) methane
  D) butane
  Show Answer
  The correct answer is A .
• Question 598: A metal that can be extracted from cassitertite is Options:
  A) cacium
  B) magnesium
  C) tin
  D) copper
  Show Answer
  The correct answer is C .
• Question 599: One of the products of the thermal decomposition of sodium trioxonitrate (V) is Options:
  A) sodium
  B) nitrogen
  C) sodium dioxonitrate (III)
  D) sodium oxide
  Show Answer
  The correct answer is C .
• Question 600: The ion that can be used as an oxidizing agent is Options:
  A) Au³⁺
  B) Fe³⁺
  C) F^-
  D) Ca²⁺
  Show Answer
  The correct answer is C .