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 1161: In the oil drop experiment, Millikan determined the? Options:
  A) charge to mass ratio of the electron
  B) mass of the electron
  C) charge of the electron
  D) mass of the proton
  Show Answer
  The correct answer is C .
• Question 1162:

  The equilibrium reaction between copper (l) chloride and chlorine at 25^oC and 1 atmosphere is represented by the equation:

  2CuCl +Cl₂ ⇌ 2 CuCl₂ ∆H = - 166 KJ. Which of the following statements is TRUE for the reaction, pressure remaining constant?

  Options:
  A) more CuCl is formed at 40^oC
  B) more CuCl₂ is formed at 10^oC
  C) Less CuCl₂ is formed at 10^oC
  D) there is no change in the amount of CuCl₂ formed at 40^oC and10^oC
  E) more CuCl is consumed at 40^oC
  Show Answer
  The correct answer is B .
• Question 1163: 25 cm³ of 0.02 M KOH neutralized 0.03 g of a monobasic organic acid having the general formula C_nH_{2n + 1} COOH. The molecular formula of the acid is?(C = 12, H = 1, O = 16) Options:
  A) HCOOH
  B) C₂H₅COOH
  C) CH₃COOH
  D) C₃H₇COOH
  Show Answer
  The correct answer is C .
• Question 1164: Ethanol is soluble in water due to the presence of a Options:
  A) Carbonyl group
  B) Hydroxyl groupd
  C) Phenyl group
  D) Methyl group
  Show Answer
  The correct answer is B .
• Question 1165:

  What is the molecular geometry of a molecule with three bonding pairs and no lone pairs around the central atom?

  Options:
  A) Tetrahedral
  B) Trigonal planar
  C) Linear
  D) Octahedral
  Show Answer
  The correct answer is B .
• Question 1166: Na₂C₂O₄ + CaCl₂ → CaC₂O₄ + 2NaCl. Given a solution of 1.9g of sodium oxalate in 50g of water at room temperature, calculate the minimum volume of 0.1 M calcium oxalate using the above equation? Options:
  A) 1.40 χ 10² dm³
  B) 14.0 χ 10² cm³
  C) 1.40 χ 10^-2 dm^-2
  D) 14.0 χ 10^-2 cm³
  Show Answer
  The correct answer is A .
• Question 1167: Which of the following equations represents an oxidizing action of sulphur dioxide? Options:
  A) SO₂ + 2HNO₂ → H₂SO₄ + 2NO₂ + heat
  B) 2SO₂ + 2H₂O + O₂ → 2H₂SO₄
  C) SO₂ + 2H₂O + CI₂ → H₂SO₄ + 2HCI
  D) SO₂ + 2H₂S → 3S + 2H₂O
  E) K₂Cr₂O₇ + H₂SO₄ + 3SO₂ → K₂SO₄ + Cr₂(SO₄)₃ + H₂O
  Show Answer
  The correct answer is D .
• Question 1168: When sugar is dissolve in ten, the reaction is accomplished by Options:
  A) positive change
  B) negative entropy change
  C) no entropy change
  D) a minimum entropy change
  Show Answer
  The correct answer is C .
• Question 1169:

  What is the chemical name for the compound CuCO${}_3$?

  Options:
  A) Copper (iii) carbonate
  B) Copper (ii) carbonate
  C) Copper (i) carbonate
  D) Copper
  Show Answer
  The correct answer is B .
• Question 1170: In a flame test for calcium, the flame appears Options:
  A) green when viewed through a blue glass
  B) blue when viewed through a blue glass
  C) orange -red when viewed through a blue glass
  D) brick-red when viewed through a blue-glass
  Show Answer
  The correct answer is D .