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 531:

  Which quantum divides shells into orbitals?

  Options:
  A) Spin
  B) Principal
  C) Azimuthal
  D) Magnetic
  Show Answer
  The correct answer is C .
• Question 532:

  The sulphide that is commonly used in coating electric fluorescent tubes is?

  Options:
  A) iron(ii)Sulphide
  B) tin(ii)sulphide
  C) Zinc Sulphide
  D) lead(iv) Sulphide
  Show Answer
  The correct answer is C .
• Question 533: If hydrogen sulphide gas is passed into a solution of a pure iron chloride, a yellow deposit appears. If the deposit is filtered, a pale green solution is left behind. The pale green solution is Options:
  A) dilute sulphuric acid
  B) dilute hydrochloric acid
  C) unreacted hydrogen sulphide in water
  D) iron (III) chloride
  E) Iron (II) chloride
  Show Answer
  The correct answer is E .
• Question 534:

  What is the common name for ethanoic acid?

  Options:
  A) Acetic acid
  B) Butyric acid
  C) Propionic acid
  D) Formic acid
  Show Answer
  The correct answer is A .
• Question 535: The four classes of hydrocarbons are? Options:
  A) ethane, ethene, ethyne and benzene
  B) alkanes, alkenes, alkynes and aromatics
  C) alkanes, alkenes, alkynes and benzene
  D) methane, ethane , propane and butane
  Show Answer
  The correct answer is B .
• Question 536: Water is poured over a white solid and a colourless neutral gas is evolved which burns with a sooty flame. The white solid is? Options:
  A) calcium
  B) calcium oxide
  C) calcium carbide
  D) sodium peroxide
  E) sodium sulphate
  Show Answer
  The correct answer is C .
• Question 537: Hypochlorous acid is used as a bleach because Options:
  A) it is a strong acid
  B) it yields chlorine readily in pure water
  C) it is an oxidising agent
  D) it is a weak acid
  E) it is a reducing agent
  Show Answer
  The correct answer is C .
• Question 538:

  When 10g of sodium hydroxide is dissolved in 1000cm³ of water, the sodium formed is approximately

  [Na = 23, H = 1, O = 16]

  Options:
  A) 0.01 mol dm^-3
  B) 0.10 mol dm^-3
  C) 0.25 mol dm^-3
  D) 0.50 mol dm^-3
  Show Answer
  The correct answer is C .
• Question 539:

  CH₃COOH_(aq) + OH^-_(aq) ↔ CH₃COO^-_(aq) + H₂O_(l)

  In the reaction above ,CH₃COO^-_(aq) is

  Options:
  A) conjugate base
  B) acid
  C) base
  D) conjugate acid
  Show Answer
  The correct answer is A .
• Question 540:

  The collision theory explains reaction rates in terms of

  Options:
  A) size of the product
  B) frequency of collision of the reactants
  C) size of reactant
  D) frequency of collision of the products
  Show Answer
  The correct answer is B .