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 1:

  

  The above reaction is an example of

  Options:
  A) a displacement reaction
  B) a neutralization reaction
  C) an elimination reaction
  D) saponification
  Show Answer
  The correct answer is B .
• Question 2:

  Aluminum hydroxide is used in the dyeing industry as a?

  Options:
  A) Dye
  B) Dispersant
  C) Salt
  D) Mordant
  Show Answer
  The correct answer is D .
• Question 3: Oxidation of concentrated hydrochloric acid with manganese (IV) oxide liberates a gas used in the? Options:
  A) manufacture of tooth pastes
  B) treatment of simple golitre
  C) vulcanization of rubber
  D) sterilization of water
  Show Answer
  The correct answer is D .
• Question 4: What is the pH of 0.001 mol dm^-3 solution of sodium hydroxide Options:
  A) 14
  B) 13
  C) 12
  D) 11
  Show Answer
  The correct answer is D .
• Question 5:

  Crude petroleum is converted to useful products by the processof?

  Options:
  A) fractional crystallization
  B) fractional distillation
  C) filtration
  D) chromatography
  Show Answer
  The correct answer is B .
• Question 6:

  What is the main environmental concern associated with sulfur dioxide emissions?

  Options:
  A) Formation of acid rain
  B) Global warming potential
  C) Depletion of the stratospheric ozone
  D) Depletion of the ozone layer
  Show Answer
  The correct answer is A .
• Question 7:

  Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth-to-mouth to each other at room temperature. The entropy in the mixture of gases is likely to

  Options:
  A) remain unchanged
  B) increase
  C) decrease
  D) change
  Show Answer
  The correct answer is B .
• Question 8: 0.07g of a hydride of carbon occupies 56.0cm³ at S.T.P. when vaporized and contains 14.29% by mass of hydrocarbon is(C = 12, H = 1) Options:
  A) CH₄
  B) C₂H₂
  C) C₂H₄
  D) C₂H₆
  E) C₃H₈
  Show Answer
  The correct answer is C .
• Question 9: A silicon -containing ore has 92% ²⁸Si, 5% ²⁹Si and 3% ³⁰Si. Calculate the relative atomic mass of the silicon. Options:
  A) 14.00
  B) 29.00
  C) 28.11
  D) 28.00
  Show Answer
  The correct answer is C .
• Question 10: In the oil drop experiment, Millikan determined the? Options:
  A) charge to mass ratio of the electron
  B) mass of the electron
  C) charge of the electron
  D) mass of the proton
  Show Answer
  The correct answer is C .