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 1871:

  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.

  Reaction of X with yeast forms the basis of the

  Options:
  A) plastic industry
  B) textile industry
  C) brewing industry
  D) soap industry
  E) dyeing industry
  Show Answer
  The correct answer is C .
• Question 1872: Catalytic hydrogenation of benzene produces Options:
  A) Oil
  B) Cyclohexene
  C) Cyclohexane
  D) Margarine
  Show Answer
  The correct answer is C .
• Question 1873: One of the major uses of alkane is Options:
  A) as domestic and industrial fuel
  B) in the hydrogenation of oils
  C) in the textile industries
  D) in the production of plastics
  Show Answer
  The correct answer is A .
• Question 1874: If an organic compound decolorizes bromine water then the compound is? Options:
  A) saturated
  B) supersaturated
  C) unsaturated
  D) a solid
  E) protonated
  Show Answer
  The correct answer is C .
• Question 1875: The minimum volume of oxygen required for the complete combustion of a mixture of 10cm ³ of CO and 15 cm ³ of H ² is Options:
  A) 25.0cm³
  B) 12.5 cm³
  C) 10.0 cm³
  D) 5.0cm³
  Show Answer
  The correct answer is C .
• Question 1876: 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 1877:

  The nucleusof a hydrogen atom consist of a?

  Options:
  A) 1 proton only
  B) 1 proton, 2 neutron
  C) 1 neutron only
  D) 1 electron only
  Show Answer
  The correct answer is A .
• Question 1878:

  MnO_2(s) + xHCl_(aq) → MnCl_2(aq) + yH₂O_(l) + zCl_2(g)

  In theequation above, what are the values of x, y and z respectively

  Options:
  A) 2, 1, 2
  B) 4, 1, 2
  C) 4, 2, 1
  D) 1, 2, 1
  Show Answer
  The correct answer is C .
• Question 1879: Which of the following does NOT contain aluminium as component? Options:
  A) Over-head cables
  B) Duralumin
  C) Container for caustic soda
  D) Container for nitric acid
  Show Answer
  The correct answer is D .
• Question 1880: Water can be obtained as the only product during Options:
  A) combustion of hydrocarbons
  B) neutralization of an acid by base
  C) combustion of hydrogen
  D) electrolysis of brine
  E) boiling water
  Show Answer
  The correct answer is C .