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 111: 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(mol^-1) Options:
  A) 54.0g
  B) 27.0g
  C) 13.5g
  D) 108.0g
  Show Answer
  The correct answer is A .
• Question 112: Which of the following alloys contain iron? Options:
  A) Duralumin and steel
  B) Brass and bronze
  C) Steel and permalloy
  D) Soft solder and duralumin
  Show Answer
  The correct answer is C .
• Question 113: Atomicity of ozone is Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is C .
• Question 114:

  Which quantum divides shells into orbitals?

  Options:
  A) Spin
  B) Principal
  C) Azimuthal
  D) Magnetic
  Show Answer
  The correct answer is C .
• Question 115: The reddish-brown rust on iron roofing sheets consists of Options:
  A) Fe³⁺(H₂O)₆
  B) FeO.H₂O
  C) Fe₂O₃.3H₂O
  D) Fe₃O₄.2H₂O
  Show Answer
  The correct answer is C .
• Question 116: C_xH_Y + 4O₂ → 3CO₂ + 2H₂O. The hydrocarbon, C_xH_Y, in the reaction above is? Options:
  A) propane
  B) propene
  C) propyne
  D) propanone
  Show Answer
  The correct answer is C .
• Question 117: 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 118:

  220g of carbon dioxide contains ----- moles

  Options:
  A) 5
  B) 6
  C) 3
  D) 4
  Show Answer
  The correct answer is A .
• Question 119: The constituents of baking powder that makes the dough to rise is Options:
  A) NaHCO₃
  B) NaOH
  C) Na₂CO₃
  D) NaCl
  Show Answer
  The correct answer is A .
• Question 120: The hydrocarbon used in the production of styrene is Options:
  A) ethyne
  B) propyne
  C) ethane
  D) ethene
  Show Answer
  The correct answer is D .