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 931: Which of the following is a measure of the average kinetic energy of the molecules of a substance? Options:
  A) Volume
  B) Mass
  C) Pressure
  D) Temperature
  Show Answer
  The correct answer is D .
• Question 932:

  Balance the following redox reaction:
  Fe${}_2$O${}_3$+ CO Fe + CO${}_2$

  Options:
  A) Fe${}_2$O${}_3$ + CO → 2Fe + 2CO${}_2$
  B) 2Fe${}_2$O${}_3$ + 3CO → 4Fe + 3CO${}_2$
  C) Fe${}_2$O${}_3$ + 2CO → 2Fe + 2CO${}_2$
  D) Fe${}_2$O${}_3$ + 3CO → 2Fe + 3CO${}_2$
  Show Answer
  The correct answer is D .
• Question 933:

  On the basis of the electrochemical series, which of these ions will show the greater tendency to be discharged at the cathode in an electrolytic cell

  Options:
  A) cu${}^{2+}$
  B) sn${}^{2+}$
  C) fe${}^{2+}$
  D) zn${}^{2+}$
  Show Answer
  The correct answer is A .
• Question 934: If concentrated sulphric acid is added to sugar and warmed gently, the sugar changes from white to brown and finally to a black mas of carbon. In this reaction, concentrated sulphuric acid is acting as ? Options:
  A) a drying agent
  B) an oxidizing agent
  C) a dehydrated agent
  D) a reducing agent
  E) a hydrolysing agent
  Show Answer
  The correct answer is C .
• Question 935:

  

  Which of the curves shown in the figure given represents the relationships between the volume(V) and pressure(P) of an ideal gas at constant temperature?

  Options:
  A) 1
  B) 2
  C) 3
  D) 4
  E) 1 and 3
  Show Answer
  The correct answer is C .
• Question 936:

  A synthetic rubber is obtained from the polymerization of

  Options:
  A) neoprene
  B) isoprene
  C) butandiene
  D) propylene
  Show Answer
  The correct answer is B .
• Question 937: In an equilibrium reaction, which of the following conditions indicates that maximum yield of the product will be obtained? Options:
  A) Equilibrium constant is very large
  B) ∆H - T∆S = O
  C) ∆ H > T ∆ S
  D) Equilibrium constant is less than zero
  Show Answer
  The correct answer is A .
• Question 938: The gas that is removed by the water in the flask is Options:
  A) O ₂
  B) SO ₂
  C) HCI
  D) H ₂
  Show Answer
  The correct answer is C .
• Question 939:

  Which of the gas laws does this graph illustrate?

  Options:
  A) Boyle
  B) Charles
  C) Gay-Lussac
  D) Graham
  Show Answer
  The correct answer is B .
• Question 940: Which of the following tests will completely identify anyone of surphur (VI) oxide, hydrogen, carbon (IV) oxide and nitrogen (II) oxide? Options:
  A) Pass each gas into water and test with blue litmus paper
  B) Pass each gas into lime water
  C) Expose each gas to atmospheric air
  D) Pass each gas to concentrated tetraoxosulphate (IV) acid
  Show Answer
  The correct answer is B .