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 1101: Which of the following is true concerning the properties of benzene and hexane? Options:
  A) Both undergo substitution reaction
  B) Both undergo addition reaction
  C) Both are solids
  D) Both can decolourized bromine water
  Show Answer
  The correct answer is A .
• Question 1102: The type of reaction that is peculiar to benzene is Options:
  A) addition
  B) hydrolysis
  C) polymerization
  D) substitution
  Show Answer
  The correct answer is D .
• Question 1103: Which of the following compounds is used as a gaseous fuel? Options:
  A) CH₃ -CH₂ -CHO₂ -COOH
  B) CH₃ -C = CH
  C) CH₃ -CH₂ -CH₂ -CH₃
  D) CH₂ -CH₂ -CH₃
  Show Answer
  The correct answer is C .
• Question 1104: The substance ZnO dissolves in sodium hydroxide solution and mineral acid solution to give soluble products in each case. ZnO is therefore referred to as Options:
  A) an allotropic oxide
  B) an amphoteric oxide
  C) a peroxide
  D) a dioxide
  Show Answer
  The correct answer is B .
• Question 1105: According to Charle's law, the volume of a gas becomes zero at Options:
  A) −100°c
  B) −273°c
  C) −373°c
  D) 0°c
  Show Answer
  The correct answer is B .
• Question 1106:

  

  Carbon (ll) oxide may be collected as shown above because it

  Options:
  A) is heavier than air
  B) is less dense than air
  C) is insoluble in water
  D) burns in oxygen to form carbon (IV) oxide
  Show Answer
  The correct answer is C .
• Question 1107: The periodic classification of elements is an arrangement of the elements in order of their Options:
  A) Atomic Weights
  B) Isotopic Weights
  C) Molecular Weights
  D) Atomic Numbers
  E) Atomic Masses
  Show Answer
  The correct answer is D .
• Question 1108:

  4g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q.

  Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?

  Options:
  A) There were more aluminium atoms in Q than P
  B) The heat given off in retarded the reaction
  C) Q generated more pressure than P during the reaction
  D) P generated more pressure than Q
  E) Q has a greater surface area for the reaction than P
  Show Answer
  The correct answer is E .
• Question 1109:

  An element, X, forms a volatile hydride XH₃ with a vapour density of 17.0. The relative atomic mass of X is?

  (H = 1)

  Options:
  A) 34.0
  B) 31.0
  C) 20.0
  D) 14.0
  Show Answer
  The correct answer is B .
• Question 1110: The number of atoms of chlorine present in 5.85g of NaCl is [Avogaro's Number = 6.02 x 10²³] Options:
  A) 6.02 x 10²²
  B) 5.85 x 10²³
  C) 6.02 x 10²³
  D) 5.85 x 10²⁴
  Show Answer
  The correct answer is A .