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 1401: The pollution from petroleum spillage in rivers and lakes can best be dispersed by Options:
  A) Pouring detergents
  B) Passing of ships through the area
  C) Pouring organic solvents
  D) Evaporation
  Show Answer
  The correct answer is A .
• Question 1402:

  What is the chemical name for the compound CuCO${}_3$?

  Options:
  A) Copper (iii) carbonate
  B) Copper (ii) carbonate
  C) Copper (i) carbonate
  D) Copper
  Show Answer
  The correct answer is B .
• Question 1403: A particle that contains 8 proton, 9 neutrons and 7 electrons could be written as? Options:
  A) O
  B) O⁺
  C) O⁺
  D) O^-
  Show Answer
  The correct answer is B .
• Question 1404: What volume of a 0.1 M H₃PO₄ will be required to neutralize 45.0 cm³ of a 0.2 M NaOH? Options:
  A) 10.0 cm³
  B) 20.0 cm³
  C) 27.0 cm³
  D) 30.0 cm³
  Show Answer
  The correct answer is D .
• Question 1405: The condition required for corrosion to take place is the presence of Options:
  A) Oxygen and Carbon (IV) oxide
  B) Water and Oxygen
  C) Water and Carbon (IV) oxide and Oxygen
  D) Water and Carbon (IV) oxide
  Show Answer
  The correct answer is B .
• Question 1406: Argon is used in gas-filled electric lamp because it helps to? Options:
  A) prevent the reduction of the lamp fillaments
  B) prevent oxidation of the lamp fillaments
  C) make the lamp fillament glow brightly
  D) keep the atmosphere in the lamp inert
  Show Answer
  The correct answer is C .
• Question 1407:

  A colourless organic compound X was burnt in excess air to give two colourless and odourless gases, Y and Z, as products. X does not decolorize blue bromine vapour, Y turns lime milky while Z gives a blue colour with copper (ll) tetraoxosulphate (IV).

  Y and Z are respectively?

  Options:
  A) CO₂ and NH₃
  B) CO and NH₃
  C) SO₂ and H₂O
  D) CO₂ and H₂O
  E) SO₂ and NH₃
  Show Answer
  The correct answer is D .
• Question 1408: Addition of dilute hydrochloride acid to an aqueous solution of a crystalline salt yield a yellow precipitate and a gas which turned dichromate paper green. The crystalline salt was probably? Options:
  A) Na₂SO₄
  B) Na₂S
  C) Na₂S₂O₃.5H₂O
  D) Na₂CO₃
  E) NaHCO₃
  Show Answer
  The correct answer is C .
• Question 1409: 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 1410: The scale of a chemical balance is made of iron plate and coated with copper electrolytically because Options:
  A) iron is less susceptible to corrosion than copper
  B) copper is twice as less susceptitible to corrosion as iron
  C) copper is less susceptible to corrosion than iron
  D) copper and iron are equally susceptible to corrosion
  Show Answer
  The correct answer is C .