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 1921: An oxidation state of or in K2CrO7 Options:
  A) 7
  B) 6
  C) 5
  D) 4
  Show Answer
  The correct answer is B .
• Question 1922: Soap lather is an example of a colloid in which a? Options:
  A) liquid is dispersed in gas
  B) solid is dispersed in liquid
  C) gas is dispersed in liquid
  D) liquid is despersed in liquid
  Show Answer
  The correct answer is C .
• Question 1923:

  

  Use the diagram above to answer this question. The activation energy of the uncatalysed reaction is

  Options:
  A) X
  B) X + Y
  C) X - Y
  D) Y
  Show Answer
  The correct answer is A .
• Question 1924: The efficiency of a solid catalyst to increase reaction rates depends on its Options:
  A) surface area
  B) solubility
  C) concentration
  D) quantity
  Show Answer
  The correct answer is A .
• Question 1925: When chlorine is passed into water and subsequently exposed to sunlight, the gas evolved is? Options:
  A) HCl
  B) HOCl
  C) O₂
  D) Cl₂O
  Show Answer
  The correct answer is C .
• Question 1926: Ammonia gas is normally dried with? Options:
  A) concentrated sulphuric acid
  B) quicklime
  C) anhydrous calcium chloride
  D) magnesium sulphate
  Show Answer
  The correct answer is B .
• Question 1927: Which of the following molecules is held together by hydrogen bond? Options:
  A) CH₄
  B) HBr
  C) H₂SO₄
  D) HF
  Show Answer
  The correct answer is D .
• Question 1928:

  Which of the following are mixtures? 

  I. Petroleum 

  II. Rubber latex 

  III. Vulcanizer's solution 

  IV. Carbon sulphide

  Options:
  A) I, II and III
  B) I, II and IV
  C) I and II only
  D) I and IV
  Show Answer
  The correct answer is A .
• Question 1929:

  Which important nitrogen-containing compound is produced in Haber's process?

  Options:
  A) NH${}_3$
  B) NO${}_2$
  C) NO
  D) HNO${}_3$
  Show Answer
  The correct answer is A .
• Question 1930: Unsaturated organic compounds are identified by decolourization of Options:
  A) silver bromine and potassium tetraoxomanganate (VII) solutions
  B) bromine water and acidified potassium tetraoxomanganate (VII) solution
  C) silver bromide solution and bromine water
  D) bromine water and alkaline potassium tetraoxomanganate (VII) solution
  Show Answer
  The correct answer is B .