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 101: The importance of sodium aluminate (III) in the treatment of water is to Options:
  A) cause coagulation
  B) neutralize acidity
  C) prevent goitre and tooth decay
  D) kill germs
  Show Answer
  The correct answer is A .
• Question 102: Which of the following statements is true about 2-methylpropane and butane Options:
  A) They are members of the same homologous series
  B) They have the same boiling point
  C) They have different number of carbon atoms
  D) They have the same chemical properties
  Show Answer
  The correct answer is A .
• Question 103: The densities of two gases, X and Y are 0.5gdm^-3 and 2.0gdm^-3 respectively. What is the rate of diffusion of X relative to Y? Options:
  A) 0.1
  B) 0.5
  C) 2.0
  D) 4.0
  Show Answer
  The correct answer is C .
• Question 104: Certain useful waxes are composed mainly of Options:
  A) amino acids
  B) glycerols
  C) alkanols
  D) alkanoates
  Show Answer
  The correct answer is B .
• Question 105:

  Which transition metal is known for its multiple colorful oxidation states and compounds used in pigments and paints?

  Options:
  A) Silver (Ag)
  B) Copper (Cu)
  C) Gold (Au)
  D) Zinc (Zn)
  Show Answer
  The correct answer is B .
• Question 106:

  What is the name of the process by which ammonia is produced on an industrial scale?

  Options:
  A) Nitrogenation
  B) Ammoniation
  C) Nitrification
  D) Haber process
  Show Answer
  The correct answer is D .
• Question 107: Which of the following properties is not peculiar to matter? Options:
  A) Kinetic energy of particles increases from solid to gas
  B) Random motion of particles increases from gas to solid
  C) Orderliness of particles increases from gas to liquid
  D) Random motion of particles increases from liquid to gas
  Show Answer
  The correct answer is B .
• Question 108: Which of the following statements applies during the electroysis of sodium hydroxide sodium hydroxide solution using platinum electrodes? Options:
  A) Na⁺ ions are discharged at the cathode
  B) Hydrogen ions are discharged at the anode
  C) the concentration of sodium hydroxide decrease at both electrode compartments
  D) the concentration of sodium hydroxide increases at the cathode only
  E) the concentration of sodium hydroxide increases at the anode only
  Show Answer
  The correct answer is D .
• Question 109: When hydrogen sulphide and sulphur dioxide are each passed in turn into a solution of potassium dichromate? Options:
  A) both gases change the colour of the solution from yellow to colourless
  B) both gases causes sulphur to be deposited
  C) only hydrogen sulphide decolourizes the solution
  D) only sulphur dioxide deposits sulphur
  E) only hydrogen sulphide deposits sulphur
  Show Answer
  The correct answer is E .
• Question 110: What is the oxidation number of Z in K₃ZCl₆? Options:
  A) -3
  B) +3
  C) -6
  D) +6
  Show Answer
  The correct answer is B .