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 1911: Which of the following ions require the largest quantity of electricity for discharge at an electrode? Options:
  A) 2.0 mole of Q ³⁺
  B) 2.5 mole of R²⁺
  C) 4.0 mole of Y^-
  D) 3.0 mole of T^-
  Show Answer
  The correct answer is A .
• Question 1912:

  X + Y → Z. The rate equation for the chemical reaction above is ((-Δ[x])/Δt) = K[X]²[Y].

  The overall order of the reaction is

  Options:
  A) 0.0
  B) 1.0
  C) 2.0
  D) 3.09
  Show Answer
  The correct answer is D .
• Question 1913:

  Which of the following is an example of a chemical change?

  Options:
  A) dissolution of salt in water
  B) rusting of iron
  C) melting of ice
  D) separating a mixture by distillation
  Show Answer
  The correct answer is B .
• Question 1914: A substance that is used as a ripening agent for fruits is Options:
  A) ethene
  B) propene
  C) methane
  D) butane
  Show Answer
  The correct answer is A .
• Question 1915: Which of the following bonds exist in crystalline ammonium chloride (NH₄Cl)? Options:
  A) Ionic and covalent
  B) Ionic and co-ordinate
  C) Ionic covalent and co-ordinate
  D) Covalent , co-ordinate and metalllic
  E) Ionic, covalent and metallic
  Show Answer
  The correct answer is C .
• Question 1916: The conversion of open chain alkanes into cycloalkanes and aromatic compounds is called Options:
  A) cracking
  B) reforming
  C) isomerization
  D) polymerization
  Show Answer
  The correct answer is B .
• Question 1917:

  n monosaccharide $\underset{Q}{\stackrel{P}{\rightleftharpoons }}$ polysaccharide -n water.

  In the process above, P and Q respectively represent

  Options:
  A) Condensation and hydrolysis
  B) Fermentation and condensation
  C) Polymerization and hydrolysis
  D) Polymerization and condensation
  Show Answer
  The correct answer is A .
• Question 1918:

  The cost of discharging 6.0g of a divalent metal, X from its salt is ₦12.00. What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?

  [X = 63, Y = 27, 1F = 96,500C]

  Options:
  A) N12.00
  B) N27.00
  C) N63.00
  D) N95.00
  Show Answer
  The correct answer is C .
• Question 1919: The hydrocarbon used in the production of styrene is Options:
  A) ethyne
  B) propyne
  C) ethane
  D) ethene
  Show Answer
  The correct answer is D .
• Question 1920: The compound produced when sodium peroxide is heated with excess sodium is Options:
  A) Na₂CO₃
  B) Na₂O
  C) NaNO₂
  D) NaOH
  Show Answer
  The correct answer is B .