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 1711: 3Cl₂ + 2NH₃ $\to$ N₂ + 6HCl. In the above reaction, ammonia acts as Options:
  A) a reducing agent
  B) an oxidizing agent
  C) an acid
  D) a catalyst
  E) a dry agent
  Show Answer
  The correct answer is A .
• Question 1712: Cathode rays causes an object placed behind a perforated anode to cast a shadow on the screen. This observation shows that the rays Options:
  A) are positively charged
  B) are negatively charged
  C) have mass
  D) travel in straight lines
  Show Answer
  The correct answer is D .
• Question 1713: The reaction of an alkene with hydrogen in the presence of catalyst is Options:
  A) a substitution reaction
  B) an oxidation reaction
  C) a nucleophilic reaction
  D) an addition reaction
  Show Answer
  The correct answer is D .
• Question 1714: It is difficult to achieve an orderly arrangement of the molecules of a gas because they Options:
  A) have no definite shape
  B) have little force of attraction between them
  C) can collide with one another in the container
  D) are too small in size
  Show Answer
  The correct answer is B .
• Question 1715: The gasification of coke is used for the manufacturing of Options:
  A) producer gas
  B) natural gas
  C) synthetic gas
  D) industrial gas
  Show Answer
  The correct answer is C .
• Question 1716: The compound that is used as an anaesthetic is Options:
  A) CCl₄
  B) CH Cl₃
  C) CH₂Cl₂
  D) CH₃Cl
  Show Answer
  The correct answer is B .
• Question 1717: When H₂S is passed into a solution of iron (III) chloride, the solution turns Options:
  A) Pale green
  B) Pale red
  C) Brown
  D) Colourless
  Show Answer
  The correct answer is A .
• Question 1718: When excess ethanol is heated to 145^oC in the presence of concentrated H₂SO₄, the product is Options:
  A) ethyne
  B) diethyl sulphate
  C) diethyl ether
  D) acetone
  Show Answer
  The correct answer is C .
• Question 1719: A suitable solvent for iodine and nephthalene is Options:
  A) carbon (IV) sulphide
  B) ethanol
  C) water
  D) benzene
  Show Answer
  The correct answer is B .
• Question 1720: 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 .