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 1811:

  What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

  Options:
  A) 8.0g
  B) 16.0g
  C) 36.0g
  D) 72.0g
  Show Answer
  The correct answer is D .
• Question 1812: How many cations will be produced from a solution of potassium aluminium tetraoxosulphate (VI)? Options:
  A) 3
  B) 4
  C) 1
  D) 2
  Show Answer
  The correct answer is D .
• Question 1813:

  Which trace gas in the atmosphere plays a significant role in the greenhouse effect?

  Options:
  A) Oxygen
  B) Argon
  C) Carbon dioxide
  D) Nitrogen
  Show Answer
  The correct answer is C .
• Question 1814: Which of the following is true concerning the properties of benzene and hexane? Options:
  A) Both undergo substitution reaction
  B) Both undergo addition reaction
  C) Both are solids
  D) Both can decolourized bromine water
  Show Answer
  The correct answer is A .
• Question 1815: Which of the following reaction is endothermic? Options:
  A) C_(s) + O_2(g) → CO_2(g)
  B) CaO_(s) + H₂O_(l) → Ca(OH)_2(s)
  C) C_(s) + H₂O_(g) → CO_(g) + H_2(g)
  D) HCl_(aq) + NaOH_(aq) → NaCl_(aq) + H₂O_(l)
  Show Answer
  The correct answer is C .
• Question 1816:

  If a solution contains 4.9g of tetraoxosulphate (VI) acid, calculate the amount of copper (II) oxide that will react with it

  [Cu = 64, O = 16, S = 32, H = 1]

  Options:
  A) 0.8g
  B) 4.0g
  C) 40.0g
  D) 80.0g
  Show Answer
  The correct answer is B .
• Question 1817: A compound contains 40.0% C, 6.7% H 53.3% O. If the molecular mass of the compound is 180, its molecular formula is [C =12, H =1,O] Options:
  A) CH₂O
  B) C₃H₆O₃
  C) C₆H₆O₃
  D) C₆H₁₂O₆
  Show Answer
  The correct answer is D .
• Question 1818: The type of iron that is best suited for welding, making nails, chains and iron rods is Options:
  A) pig iron
  B) wrought iron
  C) cast iron
  D) iron pyrites
  Show Answer
  The correct answer is B .
• Question 1819: Copper (II) tetraoxosulphate (IV) is widely used as a? Options:
  A) fertilizer
  B) fungicide
  C) disinfectant
  D) purifier
  Show Answer
  The correct answer is B .
• Question 1820: 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 .