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 1201:

  Which of the following types of bonding does not involve the formation of new substances?

  Options:
  A) Metallic
  B) Covalent
  C) Co-ordinate
  D) Electrovalent
  Show Answer
  The correct answer is A .
• Question 1202:

  ₁²D + ₁³T → ₂⁴He + ₀¹n + energy

  The reaction above illustrates

  Options:
  A) alpha decay
  B) artificial transmutation
  C) nuclear fussion
  D) nuclear fission
  Show Answer
  The correct answer is C .
• Question 1203: A pure solid usually melts? Options:
  A) over a wide range of temperature
  B) over a narrow range of temperature
  C) at a lower temperature than the impure one
  D) at the same temperature as the impure one
  Show Answer
  The correct answer is B .
• Question 1204: An iron ore is known to contain 70.0% Fe₂O₃. The obtain from 80kg of the ore is?(Fe = 56, O = 16) Options:
  A) 35.0 kg
  B) 39.2 kg
  C) 70.0 kg
  D) 78.4 kg
  Show Answer
  The correct answer is B .
• Question 1205: The oxidation state of carbon in HCOOH is Options:
  A) -1
  B) +2
  C) +3
  D) zero
  Show Answer
  The correct answer is B .
• Question 1206: What volume of 1.5M solution of KOH would contain 0.045 moles Options:
  A) 67.50 cm³
  B) 30.00 cm³
  C) 6.75 cm³
  D) 3.00 cm³
  Show Answer
  The correct answer is B .
• Question 1207:

  Which of the following represents the kind of bonding present in ammonium chloride?

  Options:
  A) ionic only
  B) covalent only
  C) ionic and dative covalent
  D) dative covalent
  Show Answer
  The correct answer is C .
• Question 1208:

  Which two gases can be used for the demonstration of the fountain experiment?

  Options:
  A) SO${}_3$ and NH${}_3$
  B) SO${}_2$ and NH${}_3$
  C) HCl and NH${}_3$
  D) SO${}_2$ and HCl
  Show Answer
  The correct answer is C .
• Question 1209: How will a metal X, which reacts explosively with air and with dilute acids be best extracted from its ores? Options:
  A) Electrolysis of solution of its salts
  B) Decomposition of its oxides
  C) Displacement from solution by an alkali metal
  D) Electroiysis of fused salt
  Show Answer
  The correct answer is D .
• Question 1210:

  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 .