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 1181: The property used in the industrial preparation of nitrogen and oxygen from air is Options:
  A) rate of diffusion
  B) density
  C) boiling point
  D) solubility
  Show Answer
  The correct answer is C .
• Question 1182: A change in the temperature of a saturated solution disturbs the equilibrium between the Options:
  A) Undissolved solute and the solvent
  B) Dissolved solute and the solvent
  C) Dissolved solute and the undissolved solute
  D) Dissolved solute and the solution
  Show Answer
  The correct answer is C .
• Question 1183:

  Which of the following statements is true for strong electrolytes?

  Options:
  A) They do not conduct electricity in the molten state
  B) They completely dissociate into ions in solution
  C) They are non-polar substances
  D) They partially dissociate into ions in solution
  Show Answer
  The correct answer is B .
• Question 1184: When platinum electrodes are used during the electrolysis of copper (ll) tetraoxosulphate (lV) solution, the solution gets progressively? Options:
  A) acidic
  B) basic
  C) neutral
  D) amphoteric
  Show Answer
  The correct answer is A .
• Question 1185: Steam changes the colour of anhydrous cobalt (II) chloride from Options:
  A) blue to pink
  B) white to red
  C) white to green
  D) blue to white
  Show Answer
  The correct answer is A .
• Question 1186:

  2X_(aq) + MnO_2(s) + 4H⁺_(aq) → X_2(g) + Mn²⁺_(aq) + 2H₂O.

  The reaction above can be used for the laboratory preparation of all halogens except fluorine because it is?

  Options:
  A) a poisionous gas
  B) an oxidizing agent
  C) electronegative in nature
  D) highly reactive
  Show Answer
  The correct answer is D .
• Question 1187:

  When heat is absorbed during a chemical reaction, the reaction is said to be

  Options:
  A) thermodynamic
  B) exothermic
  C) isothermal
  D) endothermic
  Show Answer
  The correct answer is D .
• Question 1188:

  The IUPAC name for CH${}_3$CH${}_2$COOCH${}_2$CH${}_3$ is

  Options:
  A) methylpropanoate
  B) ethylethanoate
  C) ethylpropanoate
  D) methylethanoate
  Show Answer
  The correct answer is C .
• Question 1189: Copper (II) tetraoxosulphate (VI) solution is electrolyzed using carbon electrodes. Which of the following are produced at the anode and cathode respectively ? Options:
  A) Copper and oxygen
  B) Oxygen and copper
  C) Hydrogen and copper
  D) Copper and hydrogen
  Show Answer
  The correct answer is B .
• Question 1190: Group VII elements are Options:
  A) monoatmic
  B) good oxidizing agents
  C) highly electropositive
  D) electron donors
  Show Answer
  The correct answer is B .