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 1421: Which of the following solutions will conduct the least amount of electricity? Options:
  A) 2.00 M aqueous solution of NaOH
  B) 0.01 M aqueous solution of NaOH
  C) 0.01 M aqueous solution of hexanoic acid
  D) 0.01 M aqueous solution of sugar
  Show Answer
  The correct answer is D .
• Question 1422: Which property of a reversible reaction is affected by a catalyst? Options:
  A) Heat content (enthalphy)
  B) Energy of activation
  C) Free energy change
  D) Equilibrium position
  Show Answer
  The correct answer is B .
• Question 1423: According to charles' law, the volume of a gas becomes zero at Options:
  A) 0 ^oC
  B) -100 ^oC
  C) -273 ^oC
  D) -373 ^oC
  Show Answer
  The correct answer is C .
• Question 1424:

  An element used in the production of matches is

  Options:
  A) nitrogen
  B) aluminium
  C) copper
  D) sulphur
  Show Answer
  The correct answer is D .
• Question 1425: Natural water collected from rivers and ponds contain oxygen, carbon (IV) oxide and Options:
  A) nitrogen
  B) hydrogen
  C) chlorine
  D) sulphur
  E) oxide
  Show Answer
  The correct answer is A .
• Question 1426:

  1.00 g of the oxide of metal X (atomic mass = 64) gave 0.80 g of the metal when reduced with hydrogen.

  The formula of the oxide is?

  Options:
  A) X₂O
  B) XO
  C) XO₂
  D) X₂O₃
  E) X₃O₄
  Show Answer
  The correct answer is B .
• Question 1427:

  Which of the following is a common property of non-metals?

  Options:
  A) Exist as solids at room temperature
  B) Tend to gain electrons in chemical reactions
  C) High thermal conductivity
  D) Readily form cations in chemical reactions
  Show Answer
  The correct answer is B .
• Question 1428:

  The shapes of water, ammonia, carbon (iv) oxide and methane are respectively

  Options:
  A) linear, tetrahedral, angular and pyramidal
  B) angular, pyramidal, linear and tetrahedral
  C) pyramidal, linear, tetrahedral and angular
  D) tetrahedral, angular, pyramidal and linear
  Show Answer
  The correct answer is B .
• Question 1429: A decrease in atomic size and an increase in nuclear charge across a period lead to Options:
  A) an increase in the tendency to lose electron
  B) an increase in chemical reactivity
  C) a decrease in electropositivity
  D) a decrease in covalency in bond formation
  Show Answer
  The correct answer is B .
• Question 1430:

  

  Use the options above to answer this question. Which is the structural formula for pent-2-enoic acid?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is C .