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 51:

  Burning magnesium ribbon in air removes which of the following

  (i) oxygen (ii) nitrogen (iii) argon and (iv) carbon(iv)oxide?

  Options:
  A) i and iv only
  B) i, ii, iii and iv only
  C) i only
  D) i and ii only
  Show Answer
  The correct answer is C .
• Question 52: What are the values of x, y and z respectively in the equation: xCu + yHNO₃ → xCu(NO₃)₂ + 4H₂O + zNO? Options:
  A) 4: 1: 2
  B) 3:8:2
  C) 2:8:3
  D) 8:3:2
  Show Answer
  The correct answer is B .
• Question 53: Which of the following properties is not peculiar to matter? Options:
  A) Kinetic energy of particles increases from solid to gas
  B) Random motion of particles increases from gas to solid
  C) Orderliness of particles increases from gas to liquid
  D) Random motion of particles increases from liquid to gas
  Show Answer
  The correct answer is B .
• Question 54:

  The scientist who stated that matter can be converted into energy is?

  Options:
  A) Boyle
  B) Lavoiser
  C) Avogadro
  D) Einstein
  Show Answer
  The correct answer is D .
• Question 55:

  In the preparation of oxygen by heating KCIO, in the presence of MnO${}_2$ only moderate heat is needed because the catalyst acts by ${}_2$

  Options:
  A) lowering the pressure of the reaction
  B) increasing the surface area of the reaction
  C) increasing the rate of the reaction
  D) lowering the energy barrier of the reaction
  Show Answer
  The correct answer is D .
• Question 56:

  An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

  Compound W is

  Options:
  A) a soap
  B) an oil
  C) an alkane
  D) an ester
  E) sucrose
  Show Answer
  The correct answer is D .
• Question 57:

  What volume of 0.100M sodium trioxonitrate (V) solution contains 5g of solute.

  [Na = 23, N = 14, O = 16]

  Options:
  A) 1.7 litres
  B) 0.420 litres
  C) 0.588 litres
  D) 2.35 litres
  Show Answer
  The correct answer is C .
• Question 58: 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 59: When sulphur (IV) oxide is passed into a solution of sodium hydroxide for a long time, it eventually produces a solution of Options:
  A) NaHSO₄
  B) Na₂SO₃
  C) NaHSO₃
  D) Na₂SO₄
  Show Answer
  The correct answer is B .
• Question 60:

  How many alkoxyalkanes can be obtained from the molecular formula C${}_4$H${}_{10}$O?

  Options:
  A) 4
  B) 2
  C) 1
  D) 3
  Show Answer
  The correct answer is D .