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 1:

  Which of the following pairs of substances will react further with oxygen to form a higher oxide?

  Options:
  A) CO${}_2$ and H${}_2$O
  B) NO and H${}_2$O
  C) CO and CO${}_2$
  D) SO${}_2$ and NO
  Show Answer
  The correct answer is D .
• Question 2: The bond which joins two ethanoic acid molecules in the liquid state is Options:
  A) a covalent bond
  B) an ionic bond
  C) a dative covalent bond
  D) a hydrogen bond
  Show Answer
  The correct answer is D .
• Question 3:

  

  In the graph above, the activation energy of the catalyzed reaction is

  Options:
  A) 100KJ
  B) 300KJ
  C) 250KJ
  D) 200KJ
  Show Answer
  The correct answer is A .
• Question 4: For a general equation of the nature xP + yQ → mR + nS, the expression for the equilibrium constant is Options:
  A) k [P]^x [Q]^y
  B) $\frac{[P{]}^x[Q{]}^y}{[R{]}^m[S{]}^n}$
  C) $\frac{[R{]}^m[S{]}^n}{[P{]}^x[Q{]}^y}$
  D) $\frac{m[R]n[S]}{x[P]y[Q]}$
  Show Answer
  The correct answer is C .
• Question 5: The ores that can be concentrated by flotation are Options:
  A) nitride ores
  B) sulphide ores
  C) oxide ores
  D) non-metals
  Show Answer
  The correct answer is B .
• Question 6: The salt formed from strong acid and a strong base is Options:
  A) complex
  B) neutral
  C) basic
  D) acidic
  Show Answer
  The correct answer is B .
• Question 7: An element X has electron configuration 1s² 2s² 2p⁶ 3s² 3p⁵. Which of the following statements is correct about the element? Options:
  A) lt has a completely filled p-orbital
  B) lt has 5 electrons in its outermost shell.
  C) lt belongs to group ll on the periodic table
  D) lt is a halogen
  Show Answer
  The correct answer is D .
• Question 8:

  An element X has two isotopes, ²⁰₁₀X and ²⁰₁₀X, present in the ratio 1:3. The relative atomic mass of X would be?

  Options:
  A) 20.5
  B) 21.0
  C) 21.5
  D) 22.0
  E) 22.5
  Show Answer
  The correct answer is C .
• Question 9: The general formula of an alkyl halide (which represent the halide) is? Options:
  A) C_nH_2n - ₂X
  B) C_nH_2n + ₁X
  C) C_nH_2n + ₂X
  D) C_nH_2nX
  E) C_nH_2n - 1
  Show Answer
  The correct answer is B .
• Question 10: The pollutant that contributes to the depletion of the ozone layer is Options:
  A) CFCs
  B) NO₂
  C) SO₂
  D) CO
  Show Answer
  The correct answer is A .