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 141: The fundamental difference between the three states of matter is the Options:
  A) shape of their particles
  B) number of particles in each state
  C) shape of the container they occupy
  D) degree of movement of their particles
  Show Answer
  The correct answer is D .
• Question 142: Which of the following compounds will undergo polymerization reaction? Options:
  A) C₂H₄
  B) C₂H₅COOH
  C) C₂H₆
  D) C₂H₅OH
  Show Answer
  The correct answer is A .
• Question 143: Which of the following is found in cotton Options:
  A) Starch
  B) Cellulose
  C) Fat
  D) Oil
  Show Answer
  The correct answer is B .
• Question 144: When a pressure cooker is half filled with water, and heated to boiling point, then the pressure inside the cooker will? Options:
  A) decrease, since only a fraction of the water molecules has changed to vapour
  B) remain constant, because the total number of water molecules has not changed
  C) increase, because the water molecules can now reach every part of the sealed tube
  D) decrease, since water boils under reduced pressure
  E) increase, because the water vapour molecules now strike the walls of the tube more frequently because of their increased velocity
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  The correct answer is E .
• Question 145: The knowledge of half-life can be used to Options:
  A) create an element
  B) detect an element
  C) split an element
  D) irradiate an element
  Show Answer
  The correct answer is A .
• Question 146: Which of the following sets of metals dissolves in dilute HCl? Options:
  A) Fe, Sn and Cu
  B) Mg, Fe and Cu
  C) Mg, Sn and Fe
  D) Cu, Mg and Sn
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  The correct answer is C .
• Question 147: Which of the following best explains the increase in the rate of a chemical reaction as the temperature rises? Options:
  A) The bonds in the reacting molecules are more readily broken
  B) The molecular collisions become more violent
  C) A lower proportion of the molecules has the necessary minimum energy to react
  D) The collision frequency of the molecules increase
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  The correct answer is D .
• Question 148:

  The conductivity of an acid solution depends on the

  Options:
  A) amount of ions present and their mobilities
  B) mobilities of the ions present
  C) amount of ions present
  D) temperature of the solution
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  The correct answer is A .
• Question 149: The boiling point of water is higher than that of methanol because? Options:
  A) water is oxide while methanol is an alcohol
  B) inter molecular forces in water are stronger than those in methanol
  C) water is an inorganic compound while methanol is organic
  D) water is an ionic compound while methanol is a covalent compound
  E) water is more reactive than methanol
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  The correct answer is B .
• Question 150:

  Calculate the volume in cm³ of oxygen evolved as s.t.p. when a current of 5 A is passed through acidified water for 193s

  {F = 96500 Cmol^-1, Molar volume of a gas at s.t.p. = 22.4 dm³}

  Options:
  A) 224.000 dm³
  B) 0.056 dm³
  C) 0.224 dm³
  D) 56.000 dm³
  Show Answer
  The correct answer is B .