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 1891: The correct order of increasing boiling points of the following compounds C₃H₇OH, C₇H₁₆ and C₄H₁₀ is Options:
  A) C₃H₇OH → C₄H₁₀ → C₇H₁₀
  B) C₄H₁₀ → C₇H₁₆ → C₃H₇OH
  C) C₇H₁₆ → C₃H₇OH → C₄H₁₀
  D) C₄H₁₀ → C₃H₇OH → C₇H₁₆
  Show Answer
  The correct answer is D .
• Question 1892:

  

  The arrangement above can be used for the collection of

  Options:
  A) sulphur (IV) oxide
  B) ammonia
  C) hydrogen chloride
  D) nitrogen
  Show Answer
  The correct answer is C .
• Question 1893: The mathematical expression of PH is Options:
  A) log ₁₀[OH^-]
  B) log ₁₀1/[H ₃ O⁺]
  C) log ₁₀[H ₃ O⁺]
  D) log ₁₀1/[OH ^-]
  Show Answer
  The correct answer is B .
• Question 1894:

  

  If in the graph above 1 dm³ of a saturated solution of KCL is cooled from 80^oC, the mass of crystals deposited will be  [K = 39, Cl = 35.5]

  Options:
  A) 7.45 g
  B) 14.90 g
  C) 74.50 g
  D) 149.00 g
  Show Answer
  The correct answer is D .
• Question 1895: Zinc Oxide is a Options:
  A) Basic Oxide
  B) Acidic Oxide
  C) Amphoteric Oxide
  D) Neutral Oxide
  E) Reactive Oxide
  Show Answer
  The correct answer is C .
• Question 1896: the minimum amount of energy required for a reaction to take place is Options:
  A) lattice energy
  B) ionization energy
  C) activation energy
  D) kinetic energy
  Show Answer
  The correct answer is C .
• Question 1897: The most volatile fraction obtained from fractional distillation of crude petroleum contains? Options:
  A) butane , propane and kerosene
  B) butane , propane and petrol
  C) ethane, methane and benzene
  D) methane, ethane and propane
  Show Answer
  The correct answer is D .
• Question 1898: Group 1 A metals are not found free in nature because they? Options:
  A) are of low melting and boiling points
  B) have weak metallic bonding
  C) conduct electricity and heat
  D) are very reactive
  Show Answer
  The correct answer is D .
• Question 1899: The residual solids from the fractional distillation of petroleum are used as Options:
  A) coatings of pipes
  B) raw materials for the cracking process
  C) fuel for the driving tractors
  D) fuel for jet engines
  Show Answer
  The correct answer is A .
• Question 1900:

  An aqueous solution of a metal salt, M. gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia Therefore the cation in M is

  Options:
  A) Zn
  B) Ca
  C) Al
  D) Po
  Show Answer
  The correct answer is A .