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 2151:

  

  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 2152: If the relative molecular mass of an element is not a whole number, it can be deduced that the element is Options:
  A) Naturally radioactive
  B) abundant in nature
  C) a transition metal
  D) an isotopic mixture
  Show Answer
  The correct answer is D .
• Question 2153: Which of the following dilute solutions has the lowest pH value? Options:
  A) Calcium trioxocarbonate (IV)
  B) Sodium trioxocarbonate (IV)
  C) Hydrochloric acid
  D) Ethanoic acid
  Show Answer
  The correct answer is C .
• Question 2154: Suitable reagents for the laboratory preparation nitrogen are? Options:
  A) sodium dioxonitrate (III) and ammonium chloride
  B) sodium dioxonitrate (V) and ammonium chloride
  C) sodium chloride and ammonium chloride
  D) sodium chloride and ammonium diozonitrate (III)
  Show Answer
  The correct answer is A .
• Question 2155: In the reaction NH₃ + H⁺ → NH₄⁺, the bond formed results from? Options:
  A) an electron transferred from NH₃ + H⁺
  B) an electron pair donated by NH₃
  C) an electron pair equally shared
  D) an electron pair donated by H⁺
  E) an electron tarnsferred from H⁺ to NH₃
  Show Answer
  The correct answer is B .
• Question 2156: What is the valence shell electron configuration of the element with atomic number 17? Options:
  A) 1s² 2s² 2p⁶ 3s² 3p⁴
  B) 1s² 2s² 2p⁶ 3s² 3p⁵
  C) 2s² 2p⁶
  D) 3s² 3p⁵
  Show Answer
  The correct answer is B .
• Question 2157:

  In order to electroplate spoon with silver, the arrangement of the electrolytic cell is?

  Options:
  A) the anode is a silver rod and the cathode is the spoon
  B) the anode is the spoon and the cathode is a silver rod
  C) the electrolyte is silver trioxonitrate(v)( solution and the cathode is a silver rod.
  D) the electrolyte is silver trioxonitrate(v) solution and the anode is the spoon
  Show Answer
  The correct answer is A .
• Question 2158:

  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 2159: A mixture of petrol and water can be separated through Options:
  A) centrifugation
  B) distillation
  C) the use of separating funnel
  D) the use of filter paper
  Show Answer
  The correct answer is C .
• Question 2160: Which of the following water samples will have the highest titre value when titrated for the Ca²⁺ ions using soap solution? Options:
  A) Permanently hard water after boiling
  B) emporarily hard water after boiling
  C) Rain water stored in a glass jar for two years
  D) Permanent hard water passed through permuitit
  Show Answer
  The correct answer is A .