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 911: Sulphur (IV)oxide is a strong reducing agent in the presence of water due to the formation of Options:
  A) hydroxide ion
  B) sulpgur (Vl)oxide
  C) hydrogen sulhide
  D) trioxosulphate (IV) salt
  Show Answer
  The correct answer is D .
• Question 912: Oxygen is a mixture of two isotopes O and O with relative abundances of 90% and 10% respectively. The relative atomic mass of oxygen is? Options:
  A) 16.0
  B) 16.2
  C) 17.0
  D) 18.0
  Show Answer
  The correct answer is B .
• Question 913: An acid and its conjugate base Options:
  A) can neutralise each other to form a salt
  B) differ only by a proton
  C) differ only by the opposite charges they carry
  D) are always neutral substances
  Show Answer
  The correct answer is B .
• Question 914: The shape of the S-orbital is Options:
  A) elliptical
  B) spiral
  C) circular
  D) spherical
  Show Answer
  The correct answer is D .
• Question 915: A liquid that will dissolve fat is Options:
  A) Hydrochloric acid
  B) Calcium hydroxide
  C) Kerosene
  D) Water
  Show Answer
  The correct answer is B .
• Question 916:

  The cost of discharging 6.0g of a divalent metal, X from its salt is ₦12.00. What is the cost of discharging 9.0g of a trivalent metal, Y from its salt under the same condition?

  [X = 63, Y = 27, 1F = 96,500C]

  Options:
  A) N12.00
  B) N27.00
  C) N63.00
  D) N95.00
  Show Answer
  The correct answer is C .
• Question 917:

  Using the metal activity series, the metal that can liberate hydrogen gas from steam is?

  Options:
  A) iron
  B) copper
  C) tin
  D) lead
  Show Answer
  The correct answer is A .
• Question 918: A common characteristic between zinc and the other transition elements is the ability to Options:
  A) have variable oxidation states
  B) from complex ions
  C) act as a catalyst
  D) from coloured ions
  Show Answer
  The correct answer is B .
• Question 919: Which of the following methods can be used to obtain pure water from a mixture of sand, water and methanoic acid? Options:
  A) netralization with NaOHfoolowed by filtration
  B) neutralization with NaOH followed by distillation
  C) fractional distillation
  D) filtration followed by distillation
  Show Answer
  The correct answer is D .
• Question 920: Calculate the mass of copper deposited when a current of 0.5 ampere was passed through a solution of copper(II) chloride for 45 minutes in an electrolytic cell. [Cu = 64, F = 96500Cmol^-1] Options:
  A) 0.300g
  B) 0.250g
  C) 0.2242g
  D) 0.448g
  Show Answer
  The correct answer is D .