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 111: Neutralization involves a reaction between H₃O⁺ and? Options:
  A) CI^-
  B) OH^-
  C) NO₃^-
  D) CO₃^2-
  Show Answer
  The correct answer is B .
• Question 112: The electron configuration of ₂₂X ²⁺ ion is Options:
  A) 1s² 2s²2p⁶ 3s² 3p⁶ 4s² 3d²
  B) 1s² 2s²2p⁶ 3s² 3p⁶ 4s² 3d¹
  C) 1s² 2s²2p⁶ 3s² 3p⁶
  D) 1s² 2s²2p⁶ 3s² 3p⁶ 4s²
  Show Answer
  The correct answer is D .
• Question 113: The IUPAC nomenclature of compound CH₃CH₂COOCH₂CH₃ is Options:
  A) propyl ethanoate
  B) ethyl butanoate
  C) ethyl propanoate
  D) methyl butanoate
  Show Answer
  The correct answer is C .
• Question 114: How many valence electrons are contained in the element represented ³¹₁₅P? Options:
  A) 3
  B) 5
  C) 15
  D) 31
  Show Answer
  The correct answer is B .
• Question 115: 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 116: In countries where the temperature fall below 273k, salt always spilled on the ray road in order to Options:
  A) increase the making point office
  B) increase the density of the ice
  C) make the ice impure
  D) rinse the making point of the ice
  Show Answer
  The correct answer is A .
• Question 117:

  PCl_5(g) ↔ PCl_3(g) + Cl_2(g)

  In the reaction above, a decrease in pressure will

  Options:
  A) Decelerate the reaction
  B) Increase the yield of PCl₃
  C) Increase the yield of PCl₅
  D) Accelerate the reaction
  Show Answer
  The correct answer is B .
• Question 118:

  Given that 15.00 cm³ of H₂

  SO₄ was required to completely neutralize 25.00 cm³ of 0.125 mol dm^-3 NaOH, calculate the molar concentration of the acid solution:

  Options:
  A) 0.925 mol dm^-3
  B) 0.156mol dm^-3
  C) 0.104 mol dm^-3
  D) 0.023 mol dm^-3
  Show Answer
  The correct answer is C .
• Question 119:

  Which halogen is a gas at room temperature and is pale yellow in color?

  Options:
  A) Chlorine (Cl)
  B) Fluorine (F)
  C) Iodine (I)
  D) Bromine (Br)
  Show Answer
  The correct answer is B .
• Question 120: 2-methylprop-1-ene is an isomer of Options:
  A) but-2-ene
  B) pent-1-ene
  C) 2-methylbut-2-ene
  D) 2-methylbut-1-ene
  Show Answer
  The correct answer is A .