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 property of concentrated H₂SO₄ that makes it suitable for preparing HNO₃ is its Options:
  A) boiling point
  B) density
  C) oxidizing properties
  D) dehydrating properties
  Show Answer
  The correct answer is C .
• Question 112:

  Which of the following is a primary constituent of crude oil?

  Options:
  A) Pentane
  B) Ethanol
  C) Heptane
  D) Methane
  Show Answer
  The correct answer is D .
• Question 113:

  Which organic compound is responsible for the characteristic aroma of fruits?

  Options:
  A) Alkane
  B) Alkyne
  C) Ester
  D) Amine
  Show Answer
  The correct answer is C .
• Question 114: When temporary hard water is boiled for sometime in a kettle, the inner surface of the kettle becomes coated with a deposit of Options:
  A) calcium tetraoxosulphate(VI)
  B) calcium trioxocarbonate (IV)
  C) calcium hydrogentrioxocarbonate (IV)
  D) aluminium trioxocarbonate (IV)
  Show Answer
  The correct answer is B .
• Question 115: Chlorine gas turns a damp starch-iodide paper Options:
  A) pink
  B) colourless
  C) red
  D) dark blue
  Show Answer
  The correct answer is D .
• Question 116: According to the kinetic theory, an increase in temperature causes the kinetic energy of particles to Options:
  A) Decrease
  B) Increase
  C) Remain constant
  D) Be zero
  Show Answer
  The correct answer is B .
• Question 117: Which of the following derivatives of nitrogen affords an aqueous solution having a pH of less that 7? Options:
  A) N₂O
  B) NO
  C) NO₂
  D) NaNO₃
  E) NH₃
  Show Answer
  The correct answer is C .
• Question 118:

  What is the trend for ionization energy across a period in the periodic table?

  Options:
  A) Increases from left to right.
  B) Remains constant
  C) Varies randomly
  D) Decreases from left to right
  Show Answer
  The correct answer is A .
• Question 119:

  What process would coal undergo to give coal gas, coal tar, ammoniacal liquor and coke?

  Options:
  A) Steam distillation
  B) Destructive distillation
  C) Liquefication
  D) Hydrolysis
  Show Answer
  The correct answer is B .
• Question 120: 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 .