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 381: Which volume of 0.5 M H ₂SO₄ will exactly neutralize 20 cm ³ of 0.1 M NaOH solution? Options:
  A) 2.0 cm ³
  B) 5.0 cm ³
  C) 6.8 cm ³
  D) 8.3 cm ³
  E) 10.4 cm ³
  Show Answer
  The correct answer is A .
• Question 382: In an equilibrium reaction, which of the following conditions indicates that maximum yield of the product will be obtained? Options:
  A) Equilibrium constant is very large
  B) ∆H - T∆S = O
  C) ∆ H > T ∆ S
  D) Equilibrium constant is less than zero
  Show Answer
  The correct answer is A .
• Question 383:

  Which of the following pollutants will lead to the depletion of ozone layer?

  Options:
  A) chlorofluorocarbon
  B) carbon (ii) oxide
  C) hydrogen sulphide
  D) sulphur (iv) oxide
  Show Answer
  The correct answer is A .
• Question 384:

  I. H = 1s¹ II. N = 1s² 2s² p³ III. O = 1s² 2s² p⁴ IV. Zn = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰

  From the above, which of the following pairs is like to be paramagnetic?

  Options:
  A) I and II
  B) I and III
  C) I and IV
  D) III and IV
  Show Answer
  The correct answer is A .
• Question 385: In an electrochemical cell, polarization is caused by Options:
  A) Oxygen
  B) Hydrogen
  C) Tetraoxosulphate(IV) acid
  D) Chlorine
  Show Answer
  The correct answer is B .
• Question 386: The general formula of an alkyl halide (where X represents the halide) is? Options:
  A) C_nH_2n2X
  B) C_nH_2n + ₁X
  C) C_nH_2n + ₂X
  D) C_nH_2nX
  Show Answer
  The correct answer is B .
• Question 387:

  In the reaction

  C + 2HNO₃ → CO₂ + NO₂ + NO + H₂O nitric acid is acting as?

  Options:
  A) a reducing agent
  B) a nitrating agent
  C) an oxidizing agent
  D) a catalytic agent
  E) a neutralizing agent
  Show Answer
  The correct answer is C .
• Question 388: When chlorine Is passed into water and the resulting solution exposed to sunlight, the product formed are Options:
  A) Chlorine gas and hydrogen
  B) Oxygen and oxochlorate (I) acid
  C) Chlorine gas and oxochlorate (I) acid
  D) Hydrochloric acid and oxygen
  Show Answer
  The correct answer is D .
• Question 389: Vulcanization involve the removal of Options:
  A) monometer
  B) the single bond
  C) the double bond
  D) a polymer
  Show Answer
  The correct answer is C .
• Question 390: The soft solder used for welding and plumbing is alloy of Options:
  A) lead and tin
  B) iron and tin
  C) lead and zinc
  D) iron and zinc
  Show Answer
  The correct answer is A .