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 1141: In the extraction of iron, which of the following reactions does NOT take place in the blast furnace? Options:
  A) CO₂ + C → 2CO
  B) 2Fe₂O₃ + 3C → 4Fe + 3CO₂
  C) Fe₂O₃ + 3C → 2Fe + 3CO₂
  D) CaCO₃ → CaO + CO₂
  E) CaO + SiO₂ → CaSiO₃
  Show Answer
  The correct answer is B .
• Question 1142: When a bottle of Coca-Cola is opened, bubbles of evolve. The gas is? Options:
  A) hydrogen
  B) carbon monoxide
  C) carbon dioxide
  D) sulphur oxide
  E) chlorine
  Show Answer
  The correct answer is C .
• Question 1143: The oxidation number of iodine in KIO₃ is Options:
  A) +7
  B) +3
  C) +5
  D) +6
  Show Answer
  The correct answer is C .
• Question 1144: Insoluble salts can be prepared by Options:
  A) titrating an alkali against an appropriate acid
  B) reacting an acid with trioxocarbonatr (IV) salt
  C) directing combination of the elements which make up the salt
  D) mixing two soluble compounds containing the metallic radical and the acidic radical
  Show Answer
  The correct answer is D .
• Question 1145: What weight of sodium hydroxide is required to make 500 cm³ of 0.2 M solution?(Na = 23, O = 16, H = 1) Options:
  A) 40 g
  B) 20 g
  C) 10 g
  D) 4 g
  E) 2 g
  Show Answer
  The correct answer is D .
• Question 1146:

  

  Use the graph above to answer this question. The mass of a substance, M, liberated at an electrode during electrolysis is proportional to the quantity of electricity, Q passing through the electrolyte. This is represented graphically by.

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is A .
• Question 1147: 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 1148:

  

  The compound above is

  Options:
  A) glycol
  B) primary alkanol
  C) secondary alkanol
  D) tertiary alkanol
  Show Answer
  The correct answer is C .
• Question 1149: Which of the following atoms represents deuterium? Options:
  A) No protons = 1, No of neutrons = 0, No of electrons = 0
  B) No protons = 1, No of neutrons = 0, No of electrons = 1
  C) No protons = 1, No of neutrons = 1, No of electrons = 1
  D) No protons = 1, No of neutrons = 2, No of electrons = 1
  Show Answer
  The correct answer is C .
• Question 1150: Which of the following mixture of gases is likely to burn in flame Options:
  A) neon and hydrogen
  B) nitrogen and helium
  C) helium and neon
  D) neon and nitrogen
  Show Answer
  The correct answer is A .