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 1081:

  A solution contains 20g of solute in 180g of solvent. If the solvent is water, what is the concentration of the solution in terms of mass by mass percentage

  Options:
  A) 11.%
  B) 22.2%
  C) 10%
  D) 20%
  Show Answer
  The correct answer is C .
• Question 1082:

  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 1083: The soil around a battery manufacturing factory is likely to contain a high concentration of? Options:
  A) Ca²⁺ salts
  B) Pb²⁺ salts
  C) Mg²⁺ salts
  D) Al³⁺ salts
  Show Answer
  The correct answer is B .
• Question 1084: Which of the following compounds is composed of Al, Si, O and H? Options:
  A) Epsom salt
  B) Limestone
  C) Clay
  D) Urea
  Show Answer
  The correct answer is C .
• Question 1085: A major source of oxide of oxygen is from the burning of Options:
  A) coal
  B) wood
  C) fuel
  D) chlorofluorocarbons
  Show Answer
  The correct answer is A .
• Question 1086:

  Which of the following compounds will form a solution if exposed to air?

  Options:
  A) Na₂CO₃.10H₂O
  B) NaNO₃
  C) CuSO₄
  D) CaCl₂
  E) NaSO₄.10H₂O
  Show Answer
  The correct answer is D .
• Question 1087: An acid is said to be weak if? Options:
  A) its ions are so completely dissociated that they easily drift apart
  B) the acid is not corrosive
  C) the acid has low specific gravity
  D) its ions move very slowly when in solution
  E) its ions are incompletely dissociated
  Show Answer
  The correct answer is E .
• Question 1088:

  

  The IUPAC nomenclature of the compound above is

  Options:
  A) 2-ethylpentane
  B) 3,4-dimethylhexane
  C) 2,3-dimethylhexane
  D) 2-ethylhexane
  Show Answer
  The correct answer is B .
• Question 1089: Some products of destructive distillation of coal are Options:
  A) carbon (IV) oxide and ethanoic acid
  B) trioxocarbonate (IV) acid and methanoic acid
  C) producer gas and water gas
  D) coke and ammonia liquor
  Show Answer
  The correct answer is D .
• Question 1090: A gas that can behave as a reducing agent towards chlorine and as an oxidizing agent toward hydrogen sulphide is Options:
  A) O₂
  B) NO
  C) SO₂
  D) NH₃
  E) CO₂
  Show Answer
  The correct answer is C .