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 101: During the vulcanization of rubber, sulphur is added to Options:
  A) Break down rubber polymer
  B) Lengthen the chain of rubber
  C) Bind rubber molecules together
  D) Act as a catalyst
  Show Answer
  The correct answer is C .
• Question 102:

  A solution X on mixing with AgNO₃ solution, gives a white precipitate solution in NH₃. A Solution Y, when added to X, also gives a white precipiate which is soluble on boiling. Solution Y contains?

  Options:
  A) Ag⁺ ion
  B) Pb²⁺ ion
  C) Pb⁴⁺ ion
  D) Zn²⁺ ion
  E) Al³⁺ ion
  Show Answer
  The correct answer is B .
• Question 103:

  CH₃COOH_(aq) + OH^-_(aq) ↔ CH₃COO^-_(aq) + H₂O_(l)

  In the reaction above ,CH₃COO^-_(aq) is

  Options:
  A) conjugate base
  B) acid
  C) base
  D) conjugate acid
  Show Answer
  The correct answer is A .
• Question 104: One note of a hydrocarbon 36g of carbon and its density is 20. The structure of hydrocarbon is (organic chemical) Options:
  A) CH3C = CH
  B) CH3CH = CH2
  C) CH3CH2C = CH
  D) CH33CH2CH3
  Show Answer
  The correct answer is A .
• Question 105: In the laboratory preparation of ethyl ethanoate, the water present in the mixture is removed using a solution of Options:
  A) an hydrous CaCl₄
  B) concentrated NaCO₄
  C) dilute NaOH
  D) concentrated H₄SO₄
  Show Answer
  The correct answer is D .
• Question 106: Which of the following compounds is a neutral oxide? Options:
  A) Carbon (IV) oxide
  B) Sulphur (Vl) oixide
  C) Sulphur (IV) oxide
  D) Carbon (ll) oxide
  Show Answer
  The correct answer is D .
• Question 107:

  Which of the following types of bonding does not involve the formation of new substances?

  Options:
  A) Metallic
  B) Covalent
  C) Co-ordinate
  D) Electrovalent
  Show Answer
  The correct answer is A .
• Question 108: What is the volume of energy required to burn 45cm3 of mixture at S.T.P Options:
  A) 135.0cm³
  B) 150.0cm³
  C) 45.0cm³
  D) 90.0cm³
  Show Answer
  The correct answer is D .
• Question 109:

  When 10g of sodium hydroxide is dissolved in 1000cm³ of water, the sodium formed is approximately

  [Na = 23, H = 1, O = 16]

  Options:
  A) 0.01 mol dm^-3
  B) 0.10 mol dm^-3
  C) 0.25 mol dm^-3
  D) 0.50 mol dm^-3
  Show Answer
  The correct answer is C .
• Question 110: A compound that will NOT produce oxygen on heating is? Options:
  A) potasium dioxonitrate (III)
  B) lead (IV) oxide
  C) potassium trioxochlorate (V)
  D) potassium trioxonitrate (V)
  Show Answer
  The correct answer is A .