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 411: When sodium is added to ethanol, the products are? Options:
  A) sodium hydroxide and water
  B) sodium hydroxide and hydrogen
  C) sodium ethoxide and water
  D) sodium ethoxide and hydrogen
  Show Answer
  The correct answer is D .
• Question 412: Hydrogen is readily released when dilute hydrochloric acid reacts with Options:
  A) Cu
  B) Na
  C) Au
  D) Ag
  Show Answer
  The correct answer is B .
• Question 413:

  

  Use the diagram to answer this question.

  The colour of the fountain water is

  Options:
  A) blue
  B) orange
  C) red
  D) yellow
  Show Answer
  The correct answer is C .
• Question 414: When steam is passed through red hot carbon, which of the following are produced? Options:
  A) Hydrogen oxygen and carbon (IV) oxide
  B) Hydrogen and carbon (IV) oxide
  C) Hydrogen and carbon (II) oxide
  D) Hydrogen and trioxocarbonate (IV) acid
  Show Answer
  The correct answer is C .
• Question 415: Soap lather is an example of a colloid in which a? Options:
  A) liquid is dispersed in gas
  B) solid is dispersed in liquid
  C) gas is dispersed in liquid
  D) liquid is despersed in liquid
  Show Answer
  The correct answer is C .
• Question 416: Which of the following decreases when a given mass of gas is compressed to half its initial volume? Options:
  A) Average intermolecular distance
  B) Frequency of collisions
  C) Number of molecules present
  D) Atomic radius of each particle
  Show Answer
  The correct answer is A .
• Question 417: The pollution from petroleum spillage in rivers and lakes can best be dispersed by Options:
  A) Pouring detergents
  B) Passing of ships through the area
  C) Pouring organic solvents
  D) Evaporation
  Show Answer
  The correct answer is A .
• Question 418: Which of the following can be obtained by fractional distillation? Options:
  A) Nitrogen from liquid air
  B) Sodium chloride from sea water
  C) Iodine from a solution of Iondine in carbon tetrachloride
  D) Sulphur from a solution of sulphur incarbon disulphide
  Show Answer
  The correct answer is A .
• Question 419: For iodine crystals to sublime on heating, the molecules must acquire energy that is? Options:
  A) less than the forces odf attraction in the solid
  B) equal to the forces of attraction in th solid
  C) necessary to melt the solid
  D) greater than the forces of attraction in both the solid and the liquid phases
  Show Answer
  The correct answer is D .
• Question 420:

  220g of carbon dioxide contains ----- moles

  Options:
  A) 5
  B) 6
  C) 3
  D) 4
  Show Answer
  The correct answer is A .