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 11: 50 cm³ of carbon (II) oxide was exploded with 150 cm³ of air containing 20% oxygen by volume. Which of the reactants was in excess? Options:
  A) Carbon (II) oxide
  B) Carbon (IV) oxide
  C) Oxygen
  D) Nitrogen
  Show Answer
  The correct answer is C .
• Question 12: Hydrogen is not liberated when trioxonitrate(v)acid reacts with zinc because Options:
  A) zinx is not rendered passive by acid
  B) hydrogen produced is oxidized to water
  C) oxides of nitrogen are produced
  D) all nitrates are soluble in water
  E) trioxonitrate(v)acid is a strong acid
  Show Answer
  The correct answer is E .
• Question 13: The reaction of carbide with water gives Options:
  A) ethyne
  B) ethene
  C) ethane
  D) ethanal
  Show Answer
  The correct answer is A .
• Question 14:

  The number of molecules of Carbon(iv)Oxide produced when 10.0g of CaCO${}_3$ is treated with 0.2dm${}^3$ of 1 Mole of HCL in the equation

  CaCO${}_3$ + 2HCL $\to$ CaCl${}_2$  + H${}_2$ O + CO${}_2$  , is ?

  Options:
  A) 1.00 X 10${}^{23}$
  B) 6.02 X 10${}^{23}$
  C) 6.02 X 10${}^{22}$
  D) 6.02 X 10${}^{24}$
  Show Answer
  The correct answer is C .
• Question 15: Substance employed as drying agents are usually Options:
  A) amphoteric
  B) hydroscopic
  C) efflorescent
  D) acidic
  Show Answer
  The correct answer is B .
• Question 16:

  The maximum electron in N shell is?

  Options:
  A) 2
  B) 8
  C) 18
  D) 32
  Show Answer
  The correct answer is D .
• Question 17: The IUPAC nomenclature of compound CH₃CH₂COOCH₂CH₃ is Options:
  A) propyl ethanoate
  B) ethyl butanoate
  C) ethyl propanoate
  D) methyl butanoate
  Show Answer
  The correct answer is C .
• Question 18:

  

  Use the graph above to answer this question. The mass of a substance, M, liberated at an electrode during electrolysis is proportional to the quantity of electricity, Q passing through the electrolyte. This is represented graphically by.

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 19:

  A blue litmus paper turns red when dipped into a solution. What does this indicate about the solution?

  Options:
  A) The solution is basic
  B) The solution is neutral
  C) The solution is acidic
  D) The litmus paper is faulty
  Show Answer
  The correct answer is C .
• Question 20: A burning candle produces water and Options:
  A) Carbon (II) oxide
  B) Carbon (IV) oxide
  C) Oxygen
  D) Hydrogen
  Show Answer
  The correct answer is B .