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 1321: 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 1322: The solubilites of different solutes in a given solvent can be compared by Options:
  A) plotting their solubility curves on separete axes
  B) plotting their solubility curves on the same axes
  C) plotting some of the solubility curves on the x-axis and others on the y-axis
  D) plotting their solubility curves on the x-axis only
  Show Answer
  The correct answer is B .
• Question 1323: Hardening of an oil may achieved by? Options:
  A) boiling the oil with water
  B) boiling the oil with a catalyst
  C) treating the oil with sodium hydroxide
  D) treating the oil with hydrogen and catalyst
  E) distilling oil under reduced pressure
  Show Answer
  The correct answer is D .
• Question 1324: Which of the following statement is false? Options:
  A) Acids react with some metals, liberating hydrogen
  B) Acids react with carbonates, liberating carbondioxide
  C) Acids conduct electricity and are decomposed by the current, liberating hydrogen at the anode
  D) Acids have a sour taste
  E) Acids change the colour of indicators
  Show Answer
  The correct answer is C .
• Question 1325: The atom of an element X is represented as _z^yX. The basic chemical properties of X depends on the value of Options:
  A) Y
  B) Z
  C) Y - Z
  D) Z - Y
  Show Answer
  The correct answer is B .
• Question 1326: The most suitable metal that can be used as lightning conductor is Options:
  A) silver
  B) copper
  C) iron
  D) aluminium
  Show Answer
  The correct answer is B .
• Question 1327:

  With conc H₂SO₄ as catalyst

  CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O

  Options:
  A) esterification
  B) Condensation
  C) saponification
  D) neutralization
  Show Answer
  The correct answer is A .
• Question 1328: What is observed when aqueous solutions of each of tetraoxosulphate (VI) acid, potassium trioxoiodate (V) and potassium iodide are mixed together? Options:
  A) A white precipitate is formed
  B) A green precipitate is formed
  C) The mixture remains colourless
  D) The mixture turns reddish brown
  Show Answer
  The correct answer is D .
• Question 1329:

  

  The IUPAC nomenclature for the compound above is

  Options:
  A) 4-methylpent-1-ene
  B) 3-methylpent-2-ene
  C) 2-methylpent-1ene
  D) 2-methylpent-4-ene
  Show Answer
  The correct answer is A .
• Question 1330: Which of the following ions require the largest quantity of electricity for discharge at an electrode? Options:
  A) 4.0 moles of Cl^-
  B) 3.0 moles of Na⁺
  C) 2.5 moles of Cu²⁺
  D) 2.0 moles of Al³⁺
  Show Answer
  The correct answer is C .