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 621: 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 622: An element with atomic number twelve is likely to be Options:
  A) electrovalent with a velocity of 1
  B) electrovalent with a valency of 2
  C) covalent with a valency of 2
  D) covalent with valency of 4
  Show Answer
  The correct answer is B .
• Question 623: The energy value of petrol can be determined by Options:
  A) Bomb calorimeter
  B) Catalytic cracker
  C) Fractionating column
  D) Thermometer
  Show Answer
  The correct answer is C .
• Question 624: The solvent used for removing grease stain is Options:
  A) turpentine
  B) ammonia solution
  C) ethanol
  D) solution of borax in water
  Show Answer
  The correct answer is B .
• Question 625: Which of the following in aqueous solution is neutral to litmus? Options:
  A) NH₄CI
  B) NaCO₃
  C) FeCl₃
  D) NaCl
  Show Answer
  The correct answer is D .
• Question 626: The principle of column chromatography is based on the ability of the constituents to Options:
  A) move at different speeds in the column
  B) dissolve in each other in the column
  C) react with the solvent in the column
  D) react with each other in the column
  Show Answer
  The correct answer is A .
• Question 627: What volume of 11.0 M hydrochloric acid must be dilute to obtain 1 dm³ of 0.05 M acid? Options:
  A) 0.05 dm³
  B) 0.10 dm³
  C) 0.55 dm³
  D) 11.0 dm³
  Show Answer
  The correct answer is A .
• Question 628: The acid used in electrolysis of water is dilute Options:
  A) HNO₃
  B) CH₃COOH
  C) H₂SO₄
  D) HCl
  Show Answer
  The correct answer is C .
• Question 629:

  Which of the following is a physical change?

  Options:
  A) Exposing white phosphorus to air
  B) Burning kerosene
  C) Dissolving calcium in water
  D) Freezing ice cream
  Show Answer
  The correct answer is D .
• Question 630: A change in temperature of a saturated solution disturb the equilibrium between the Options:
  A) Dissolved solute and the solvent
  B) Solvent and undissolved solute
  C) Dissolved solute and undissolved solute
  D) Dissolved solute and the solution
  Show Answer
  The correct answer is C .