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 221: Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series? Options:
  A) Copper
  B) Iron
  C) Lead
  D) Potassium
  E) Zinc
  Show Answer
  The correct answer is D .
• Question 222:

  

  The compound above is

  Options:
  A) glycol
  B) primary alkanol
  C) secondary alkanol
  D) tertiary alkanol
  Show Answer
  The correct answer is C .
• Question 223: Which of the following decrease when a given mass of gas is compressed to half its initial volume? Options:
  A) Atomic radius of each
  B) Average intermolecular distance
  C) Frequency of collisions
  D) Number of molecules presents
  Show Answer
  The correct answer is B .
• Question 224:

  If 1 litre of 2.2M sulphuric acid is poured into a bucket containing 10 litres of water and the resulting solution mixed thoroughly, the resulting sulphuric acid concentration will be

  Options:
  A) 2.2M
  B) 1.1M
  C) 0.22M
  D) 0.11M
  Show Answer
  The correct answer is C .
• Question 225:

  

  In the above experiment X is

  Options:
  A) pure nitrogen
  B) a mixture of nitrogen and oxygen
  C) a mixture of nitrogen and carbondioxide
  D) a mixture of oxygen and inert gases
  E) a mixture of nitrogen and inert gases
  Show Answer
  The correct answer is E .
• Question 226:

  A dense white fume is formed when ammonia gas reacts with

  Options:
  A) O_2(g)
  B) H_2(g)
  C) Cl_2(g)
  D) HCl_(g)
  Show Answer
  The correct answer is D .
• Question 227:

  The maximum electron in N shell is?

  Options:
  A) 2
  B) 8
  C) 18
  D) 32
  Show Answer
  The correct answer is D .
• Question 228:

  C_(s) + 2S_(g) → CS_2(g)

  ΔH = +89 kJ mol^-1

  The chemical equation above implies that

  Options:
  A) each of carbon and sulphur has 89 kJ of energy
  B) both carbon and sulphur contribute 89 kJ of energy
  C) 89 kJ of energy is released
  D) 89 kJ of energy is absorbed
  Show Answer
  The correct answer is D .
• Question 229:

  Consider the reaction: A + 2B${}_{(g)}\rightleftharpoons$ 2C + D${}_{(g)}$ ($\mathrm{\Delta }$H = +ve)

  What will be the effect of decrease in temperature on the reaction?

  Options:
  A) Rate of backward reaction will increase
  B) The equilibrium constant will shift
  C) Rates of forward and backward reactions are not affected
  D) Rate of forward reaction will increase
  Show Answer
  The correct answer is A .
• Question 230: The fuming of kettles is caused by the presence in the water of Options:
  A) calcium tetraoxosulphate (IV)
  B) calcium hydrogentrionocarbonate (IV)
  C) calcium hydroxide
  D) calcium trioxocarbonate (IV)
  Show Answer
  The correct answer is B .