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 41: Oxygen-demanding waste are considered to be a water pollutant because they? Options:
  A) deplete oxygen which is necessary for the survival of aquatic organism
  B) increase oxygen which is necessary for survival of aquatic organism
  C) increase other gaseous substances which are necessary for the survival of aquatic organisms
  D) deplete other gaseous species which is necessary for the survival of aquatic organisms
  Show Answer
  The correct answer is A .
• Question 42: Which of the following is used to hasten the ripening of fruit? Options:
  A) Ethene
  B) Ethanol
  C) Ethyne
  D) Ethane
  Show Answer
  The correct answer is A .
• Question 43: Calcium tetraoxosulphate (VI) dissolves in water only sparingly to form a Options:
  A) solution
  B) suspension
  C) precipitate
  D) colloid
  Show Answer
  The correct answer is C .
• Question 44: Bronze is an alloy of? Options:
  A) silver and copper
  B) silver and gold
  C) copper and nickle
  D) copper and zinc
  E) copper and tin
  Show Answer
  The correct answer is E .
• Question 45: Coal gas is made up of carbon (II) oxide, hydrogen and? Options:
  A) nitrogen
  B) air
  C) argon
  D) methane
  Show Answer
  The correct answer is D .
• Question 46:

  

  In the diagram above, the gas produced is

  Options:
  A) NO
  B) NO₂
  C) N₂O
  D) N₂O₄
  Show Answer
  The correct answer is A .
• Question 47:

  The nucleusof a hydrogen atom consist of a?

  Options:
  A) 1 proton only
  B) 1 proton, 2 neutron
  C) 1 neutron only
  D) 1 electron only
  Show Answer
  The correct answer is A .
• Question 48:

  The salt that reacts with dilute hydrochloric acid to produce a pungent smelling gas which decolourizes acidified purple potassium tetraoxomanganate (VII) solution is

  Options:
  A) Na${}_2$SO${}_4$
  B) Na${}_2$SO${}_3$
  C) Na${}_2$S
  D) Na${}_2$CO${}_3$
  Show Answer
  The correct answer is B .
• Question 49: The formula for ethyl butanoate is Options:
  A) C₃H₇COOC₂H₅
  B) C₂H₅COOC₃H₇
  C) C₄H₉COOC₂H₅
  D) C₂H₅COOC₄H₉
  Show Answer
  The correct answer is A .
• Question 50: Which quantum number divides shells into orbitals? Options:
  A) principal
  B) Arzimuthal
  C) Magnetic
  D) Spin
  Show Answer
  The correct answer is B .