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 1461:

  A solution contains 20g of solute in 180g of solvent. If the solvent is water, what is the concentration of the solution in terms of mass by mass percentage

  Options:
  A) 11.%
  B) 22.2%
  C) 10%
  D) 20%
  Show Answer
  The correct answer is C .
• Question 1462:

  Beryllium and Aluminium have similar properties because they

  Options:
  A) are both metals
  B) belong to the same group
  C) belong to the same period
  D) are positioned diagonally to each other
  Show Answer
  The correct answer is D .
• Question 1463: Which of the following gives a precipitate when treated with NaOH solution? Options:
  A) AlCl₃
  B) NH₄CL
  C) CH₃COONa
  D) Na₂CO₃
  Show Answer
  The correct answer is A .
• Question 1464: 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 1465:

  According to the kinetic theory of gases, the pressure exerted by a gas is due to

  Options:
  A) The vibrations of gas particles.
  B) The weight of the gas particles
  C) The attractive forces between gas particles
  D) The collisions of gas particles with the container walls
  Show Answer
  The correct answer is D .
• Question 1466:

  A substance that is used as a ripening agent for fruits is

  Options:
  A) ethene
  B) propane
  C) methane
  D) butane
  Show Answer
  The correct answer is A .
• Question 1467: 100 cm³ of oxygen is made to react with 50 cm ³ of hydrogen, and the whole reaction mixture was then passed through anhydrous calcium chloride. What is the volume of gas left? Options:
  A) 5 cm³
  B) 25 cm³
  C) 50 cm³
  D) 75 cm³
  E) 100 cm³
  Show Answer
  The correct answer is D .
• Question 1468: To make coloured glasses, small quantities of oxides of metals which form coloured silicates are often added to the reaction mixture consisting of Na₂CO₃ and SiO₂. Such a metals is a?. Options:
  A) pottasium
  B) barium
  C) zinc
  D) copper
  Show Answer
  The correct answer is D .
• Question 1469: The empirical formula of an oxide of nitrogen containing 30.4 per cent of nitrogen is (N=14.0,O=16.0) Options:
  A) N₂O₂
  B) NO
  C) NO₂
  D) N₂O
  E) N₂O₃
  Show Answer
  The correct answer is C .
• Question 1470: Ethyne is passed through a hot tube containing organo-nickel catalyst to produce Options:
  A) isoprene
  B) polythene
  C) ethanol
  D) benzene
  Show Answer
  The correct answer is D .