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 1: Hydrogen is used in oxy-hydrogen flames for melting metals because it Options:
  A) evolves a lot of heat when burnt
  B) combines explosively with oxygen
  C) is a very light gas
  D) is a rocket fuel
  Show Answer
  The correct answer is A .
• Question 2: The type of reaction that is peculiar to benzene is Options:
  A) addition
  B) hydrolysis
  C) polymerization
  D) substitution
  Show Answer
  The correct answer is D .
• Question 3:

  An element has an atomic number of 8 and a mass number of 16. How many neutrons does this element have?

  Options:
  A) 24
  B) 16
  C) 8
  D) 32
  Show Answer
  The correct answer is C .
• Question 4: Water can be obtained as the only product during the Options:
  A) combustion of hydrocarbons
  B) neutraliization of an acid by base
  C) combustion of hydrogen
  D) electrolysis of brine
  Show Answer
  The correct answer is C .
• Question 5:

  

  Use the option above to answer this question. The graph that describes a zero order reaction is

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .
• Question 6: The partial pressure of oxygen in a sample of air is 452mmHg and the total pressure is 780mmHg. What is the mole fraction of oxygen? Options:
  A) 0.203
  B) 0.579
  C) 2.060
  D) 5.790
  Show Answer
  The correct answer is B .
• Question 7:

  What is the chemical name for the compound CuCO${}_3$?

  Options:
  A) Copper (iii) carbonate
  B) Copper (ii) carbonate
  C) Copper (i) carbonate
  D) Copper
  Show Answer
  The correct answer is B .
• Question 8: Which of the following bonds exist in crystalline ammonium chloride (NH₄Cl)? Options:
  A) Ionic and covalent
  B) Ionic and co-ordinate
  C) Ionic covalent and co-ordinate
  D) Covalent , co-ordinate and metalllic
  E) Ionic, covalent and metallic
  Show Answer
  The correct answer is C .
• Question 9: A noble gas with a high power of fog penetration used in aerodrome beacons is Options:
  A) krpton
  B) argon
  C) helium
  D) neon
  Show Answer
  The correct answer is D .
• Question 10: A liquid begins to boil when? Options:
  A) its vapour pressure is equal to the vapour pressure of its solid at the given temperature
  B) molecules start escaping from its surface
  C) its vapour pressure equals the atmosphere pressure
  D) its volume is sightly increased
  Show Answer
  The correct answer is C .