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 1591:

  What volume of oxygen will remain after reacting 8cm of hydrogen gas with 20cm of oxygen gas

  Options:
  A) 10cm${}^3$
  B) 12cm${}^3$
  C) 14cm${}^3$
  D) 16cm${}^3$
  Show Answer
  The correct answer is D .
• Question 1592: A white solid suspected to be lead trioxonitrate (V) zinc trioxocarbonate (IV) or calcium trioxocabonate (IV) was heated strongly. Its residue which was yellow when hot and white when cold is? Options:
  A) lead (II) oxide
  B) calcium oxide
  C) zinc oxide
  D) lead nitrate
  Show Answer
  The correct answer is C .
• Question 1593: 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 1594: The balanced equation for the reaction of tetraoxosulphate(VI)acid with aluminium hydroxide to give water and aluminium tetraoxosulphate(VI) is Options:
  A) H₂SO₄ + Al(OH)₂ $\to$ 2H₂O + AlSO₄
  B) 3H₂SO₄ + 2Al(OH)₃ $\to$ 6H₂O + Al₂(SO₄)₃
  C) 3H₂SO₄ + 2AlH $\to$ 6H₂O + Al(SO₄)₃
  D) 3H₂ SO₄ + 2Al(OH)₃ $\to$ Al(SO₄)₃
  E) H₂SO₄ + Al(OH)₃ $\to$ H₂O + Al₂(SO₄)₃
  Show Answer
  The correct answer is B .
• Question 1595: Due to the high reactivity of sodium, it is usually stored under Options:
  A) water
  B) mercury
  C) paraffin
  D) phenol
  Show Answer
  The correct answer is C .
• Question 1596: An example of oxidation - reduction enzyme is Options:
  A) amylase
  B) protease
  C) lipase
  D) dehydrogenase
  Show Answer
  The correct answer is D .
• Question 1597:

  1.00 g of the oxide of metal X (atomic mass = 64) gave 0.80 g of the metal when reduced with hydrogen.

  The formula of the oxide is?

  Options:
  A) X₂O
  B) XO
  C) XO₂
  D) X₂O₃
  E) X₃O₄
  Show Answer
  The correct answer is B .
• Question 1598:

  2-methylprop-1-ene is a structuralisomer of?

  Options:
  A) But-1-yne
  B) 2-methyl But-1-ene
  C) 3-methyl prop-1-yne
  D) But-2-ene
  Show Answer
  The correct answer is D .
• Question 1599: Which of the following types of reactions takes place between C₂H₄ and the halogens? Options:
  A) Substitution
  B) Polymerization
  C) Addition
  D) Saponification
  E) Oxidation
  Show Answer
  The correct answer is C .
• Question 1600: Which of the following tests would confirm-unequivocally that a solution X contain the sulphate ion if it gives with Options:
  A) silver nitrates solution, a white precipates insoluble in dilute HNO₃
  B) barium chloride solution, a white precipitate insoluble in dilute H₂SO₄
  C) barium chloride solution, a white precipitate insoluble in dilute HCl
  D) barium chloride solution a white precipitate soluble in dilute ammonia
  E) barium chloride solution a white precipitate insoluble in dilute HCl
  Show Answer
  The correct answer is C .