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 211:

  Atoms of element X (with 2 electrons in the outer shell). combine with atoms of Y (with 7 electrons in the outer shell).

  Which of the following statements is FALSE? The compound formed

  Options:
  A) has formula XY
  B) is likely to be ionic
  C) contains X²⁺ ions
  D) contains Y^- ions
  Show Answer
  The correct answer is A .
• Question 212: Which of the following would support the conclusion that a solid sample is a mixture? Options:
  A) the solid can be ground to a fine powder
  B) the density of the solid is 2.25 g dm³
  C) the solid has a melting range of 300^oC to 375^oC
  D) the solid absorbs moisture from the atmosphere
  Show Answer
  The correct answer is C .
• Question 213: Polystyrene is widely used as packaging materials for fragile objects during transportation because of its Options:
  A) ligjtness
  B) low density
  C) high density
  D) high compressibility
  Show Answer
  The correct answer is D .
• Question 214:

  Which of the following are mixtures?

  i. Petroleum
  ii. Rubber latex
  iii. Vulcanizer's solution
  iv. Carbon (II) sulphide

  Options:
  A) i, ii and iii
  B) i, ii and iv
  C) i and ii only
  D) i and iv
  Show Answer
  The correct answer is A .
• Question 215: An undesirable paraffin in the petroleum industry which is particularly prone to knocking is? Options:
  A) iso-octane
  B) n-heptane
  C) iso-heptane
  D) n-octane
  Show Answer
  The correct answer is B .
• Question 216:

  

  In the diagram above the activation energy is represented by

  Options:
  A) y - x
  B) x
  C) x - z
  D) y
  Show Answer
  The correct answer is A .
• Question 217: The pair of organic compounds that are isomers is Options:
  A) Benzene and methylbenzene
  B) Trichloromethane and tetrachloromethane
  C) Ethanol and propane
  D) But-1-ene and but-2-ene
  Show Answer
  The correct answer is D .
• Question 218: The leachate of a certain ash is used in local soap because it contain Options:
  A) sodium chloride and potassium hydroxide
  B) sodium hydroxide
  C) potassium hydroxide
  D) soluble carbonates and hydrogen carbonate
  Show Answer
  The correct answer is B .
• Question 219: Fluorine does not occur in the free state in nature because Options:
  A) it is a poisonous gas
  B) it belongs to the halogen family
  C) it is inert
  D) of its high reactivity
  Show Answer
  The correct answer is D .
• Question 220: Which of the following compounds can exist as geometric isomers? Options:
  A) 2-methylbut-2ene
  B) But-2-ene
  C) But-1-ene
  D) CI-C-Br
  Show Answer
  The correct answer is B .