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 1061:

  Which of the following substances is NOT hygroscopic?

  Options:
  A) Salt
  B) Sugar
  C) Silica gel
  D) Aluminum
  Show Answer
  The correct answer is D .
• Question 1062: How many hydrogen atoms does a single ring cycloalkane have less than the corresponding open-chain alkane? Options:
  A) Two
  B) Three
  C) Four
  D) One
  Show Answer
  The correct answer is A .
• Question 1063: What type of bond exits between an element X with atomic number 12 and Y with atomic number 17? Options:
  A) Electrovalent
  B) Metallic
  C) Covalent
  D) Dative
  Show Answer
  The correct answer is A .
• Question 1064: Which group of elements forms hydrides that are pyramidal in structure? Options:
  A) III
  B) IV
  C) V
  D) VI
  Show Answer
  The correct answer is C .
• Question 1065:

  The substance often used for vulcanization of rubber is?

  Options:
  A) Chlorine
  B) Hydrogen peroxide
  C) Sulphur
  D) Tetraoxosulphate(vi) acid
  Show Answer
  The correct answer is C .
• Question 1066: Mineral acids are usually added to commercial hydrogen peroxide to Options:
  A) oxidize it
  B) decompose it
  C) minimize its decomposition
  D) reduce it to water and oxygen
  Show Answer
  The correct answer is C .
• Question 1067:

  A colourless organic compound X was burnt in excess air to give two colourless and odourless gases, Y and Z, as products. X does not decolorize blue bromine vapour, Y turns lime milky while Z gives a blue colour with copper (ll) tetraoxosulphate (IV).

  Y and Z are respectively?

  Options:
  A) CO₂ and NH₃
  B) CO and NH₃
  C) SO₂ and H₂O
  D) CO₂ and H₂O
  E) SO₂ and NH₃
  Show Answer
  The correct answer is D .
• Question 1068:

  The mass of silver deposited when a current of 10a is passed through a solution of silver salt for 4830s is

  [Ag = 108, F = 96500 c mol^-1]

  Options:
  A) 108.0g
  B) 54.0g
  C) 27.0g
  D) 13.5gq
  Show Answer
  The correct answer is B .
• Question 1069:

  

  The figure above shows the electrolysis of molten sodium chloride. Z is the

  Options:
  A) anode where the Cl${}^{-}$ ions are oxidized
  B) cathode where the Cl${}^{-}$ ions are reduced
  C) anode where the Na${}^{+}$ ions are reduced
  D) cathode where the Na${}^{+}$ ions are oxidized
  Show Answer
  The correct answer is A .
• Question 1070: Which of the following ions is a pollutant in drinking water even in trace amounts? Options:
  A) Ca²⁺
  B) Hg²⁺
  C) Mg²⁺
  D) Fe²⁺
  Show Answer
  The correct answer is B .