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 51:

  0.16g of methane when burnt raises the temperature of 100g of water by 40°C. What is the of combustion of methane when if the heat capacity of water is 4.2 Jg^-1°C^-1?

  (CH₄ = 16)

  Options:
  A) 1,160 kJ mol^-1
  B) 1,180 kJ mol^-1
  C) 1,560 kJ mol^-1
  D) 1,600kJ mol^-1
  E) 1,680 kJ mol^-1
  Show Answer
  The correct answer is E .
• Question 52: Water for town supply is chlorinated to make it free from? Options:
  A) bad odour
  B) bacteria
  C) temporary hardness
  D) permanent hardness
  Show Answer
  The correct answer is B .
• Question 53:

  Zn_(s) + CuSO_4(aq) $\to$ ZnSO_4(aq) + Cu_(s)

  In the reaction above, the oxidizing agent is

  Options:
  A) CuSO_4(aq)
  B) ZnSO_4(aq)
  C) Cu_(s)
  D) Zn_(s)
  Show Answer
  The correct answer is A .
• Question 54:

  2H${}_2$ + O${}_2$ 2H${}_2$O

  From the equationabove, calculate the volume of unreacted oxygen gas if a mixture of 50cm${}^3$ of hydroden and 75cm${}^3$ of oxygen are involved

  Options:
  A) 85cm${}^3$
  B) 50cm${}^3$
  C) 125cm${}^3$
  D) 55cm${}^3$
  Show Answer
  The correct answer is B .
• Question 55:

  One of the following is not a physical property of monosaccharides?

  Options:
  A) Monosaccharides get charred when heated
  B) Monosaccharides are water-soluble, sweet substances
  C) They are highly vital to the exploration of metals
  D) They can be reduced to sugar alcohols
  Show Answer
  The correct answer is C .
• Question 56: Addition of an aqueous solution of a salt gives a white precipitate. The salt is likely to be a? Options:
  A) nitrate
  B) carbonate
  C) chloride
  D) sulphide
  Show Answer
  The correct answer is B .
• Question 57:

  (I). 3CuO(s) + 2NH3(g) -----> 3Cu(s) + 3H2O(l) + N2(g) 

  (II). 2NH3(g) + 3Cl2(g) -----> 6HCl(g) + N2(g) 

  (III). 4NH3(g) + 3O2(g) -----> 6H2O(l) + N2(g) 

  The reactions represented by the equations above demonstrate the

  Options:
  A) basic properties of ammonia
  B) acidic properties of ammonia
  C) reducing properties of ammonia
  D) oxidizing properties of ammonia
  Show Answer
  The correct answer is C .
• Question 58:

  What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)?

  Options:
  A) Fractional crystallization
  B) Fractional distillation
  C) Filtration
  D) Evaporation
  Show Answer
  The correct answer is A .
• Question 59: The number of hydroxonium ions produced by one molecule of an acid in aqueous solution is its Options:
  A) basicity
  B) acid strength
  C) pH
  D) concentration
  Show Answer
  The correct answer is B .
• Question 60: If concentrated sulphric acid is added to sugar and warmed gently, the sugar changes from white to brown and finally to a black mas of carbon. In this reaction, concentrated sulphuric acid is acting as ? Options:
  A) a drying agent
  B) an oxidizing agent
  C) a dehydrated agent
  D) a reducing agent
  E) a hydrolysing agent
  Show Answer
  The correct answer is C .