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 1611:

  200 cm³ of air was passed over heated copper in a syringe several times to produce copper (II) oxide.

  When cooled, the final volume of air recorded was 158cm³. Estimate the percentage of oxygen in the air?

  Options:
  A) 31%
  B) 27%
  C) 21%
  D) 19%
  Show Answer
  The correct answer is C .
• Question 1612:

  The IUPAC name of the compound CF${}_3$CHBrCl is

  Options:
  A) 2-chloro-2-bromo-1,1,1-trifluoroethane
  B) 2-bromo-2-chloro-1,1,1-trifluoroethane
  C) 1-bromo-1-chloro-2,2,2-trifluoroethane
  D) 1,1,1-trifluoro-2-bromo-2-chloroethane
  Show Answer
  The correct answer is B .
• Question 1613: Which of the following conduct electricity? Options:
  A) sulfur
  B) graphite
  C) diamond
  D) red phosphorus
  E) yellow phosphorus
  Show Answer
  The correct answer is B .
• Question 1614:

  

  The above diagram gives the potential energy profile of the catalyst and uncatalysed reactions of X_(g) + Y_(g) → XY_(g). Deduce the respective activation energies in KJ of the catalysed and uncatalysed reverse reactions: XY(g) → X_(g) + Y_(g)

  Options:
  A) 300, 500
  B) 500, 300
  C) -300, -500
  D) -500, -300
  Show Answer
  The correct answer is A .
• Question 1615:

  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 1616:

  In the electrolysis of dilute sulphuric acid using platinum electrodes, the products obtained at the anode and cathode are:

  Anode Cathode

  Options:
  A) Sulphur hydrogen
  B) Hydrogen oxygen
  C) Oxygen Hydrogen
  D) Hydrogen sulphate ions
  E) Sulphur oxygen
  Show Answer
  The correct answer is C .
• Question 1617: The brown coloration in nitric acid prepared in the laboratory can be removed by? Options:
  A) heating the acid
  B) bubbling air through the acid
  C) cooling the acid
  D) adding a decolorizing agent
  E) adding a base
  Show Answer
  The correct answer is B .
• Question 1618: When sodium reacts with water, the resulting solution is Options:
  A) Weakly acidic
  B) Neutral
  C) Acidic
  D) Alkaline
  Show Answer
  The correct answer is D .
• Question 1619:

  What number of moles of Cu ²⁺ will be deposited by 360 coulombs of electricity?

  [f = 96500 C mol ^-1]

  Options:
  A) 5.36 x 10 ^-4 mole
  B) 1. 87 x 10 10 ^-3 mole
  C) 9. 35 x 10 ^-4 mole
  D) 3. 73 x 10 ^-3
  Show Answer
  The correct answer is B .
• Question 1620: The arrangement of particles in crystal lattices can be studied using Options:
  A) X-rays
  B) $\beta$-rays
  C) $\alpha$-rays
  D) $\gamma$-rays
  Show Answer
  The correct answer is A .