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 2161: In which of the following processes is iron being oxidized?1 Fe + H₂SO₄ → FeSO₄ +H₂2 FeSO₄ + H₂S → FeS + H₂SO₄3 2FeCI₂ + Cl₂ → 2FeCl₃4 2FeCl₃ + SnCl₂ + → 2FeCl₂ + SnCl₄ Options:
  A) 1 only
  B) 2 only
  C) 3 only
  D) 1 and 3
  E) 2 and 4
  Show Answer
  The correct answer is D .
• Question 2162: Millikan's contributions to the development of atomic theory is the determination of Options:
  A) charge on electron
  B) positive rays
  C) charge to mass ratio
  D) cathode rays
  Show Answer
  The correct answer is A .
• Question 2163:

  0.1 faraday of electricity deposited 2.95 g of nickel during electrolysis of an aqueous solution.

  Calculate the number of moles of nickel that will be deposited by 0.4 faraday? (Ni = 58.7)

  Options:
  A) 0.20
  B) 0.30
  C) 0.04
  D) 5.87
  Show Answer
  The correct answer is A .
• Question 2164: Helium is often used in observation balloons because it is? Options:
  A) light and combustible
  B) light and non-combustible
  C) heavy and combustible
  D) heavy and non-combustible
  Show Answer
  The correct answer is B .
• Question 2165: Which of the following are isomers? Options:
  A) Ethanol and dimethyl ether
  B) Benzene and methybenzene
  C) Ethanol and propanone
  D) Trichloromethane and tetrachloromethane
  Show Answer
  The correct answer is A .
• Question 2166: If one of the following oxides is heated with hydrogen or carbon using a bunsen burner, it is not reduced to the metal. Which one is it? Options:
  A) Lead oxide
  B) Magnesium oxide
  C) Copper oxide
  D) Tin oxide
  E) Iron oxide
  Show Answer
  The correct answer is B .
• Question 2167: Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series? Options:
  A) Copper
  B) Iron
  C) Lead
  D) Potassium
  E) Zinc
  Show Answer
  The correct answer is D .
• Question 2168: Detergents are more advantageous than soaps in hard water districts because Options:
  A) on treatment with hard water they either form soluble calcium salts or do not react with calcium ion
  B) on treatment with hard water they form soluble calcium salts
  C) on treatment with hard water they form sodium salts
  D) on treatment with hard water they are converted into soaps
  E) on treatment with hard water they form more lather than soaps does
  Show Answer
  The correct answer is A .
• Question 2169: Synthesis gas is a mixture of Options:
  A) CH₄ and H₂O
  B) CH₄ and H₂
  C) CO₂ and H₂
  D) CO and H₂
  Show Answer
  The correct answer is D .
• Question 2170: Unsaturated organic compounds are identified by decolourization of Options:
  A) silver bromine and potassium tetraoxomanganate (VII) solutions
  B) bromine water and acidified potassium tetraoxomanganate (VII) solution
  C) silver bromide solution and bromine water
  D) bromine water and alkaline potassium tetraoxomanganate (VII) solution
  Show Answer
  The correct answer is B .