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:

  N₂O_4(g) ↔ 2NO_2(g) ΔH = +ve

  In the reaction above, an increase in temperature will

  Options:
  A) increase the value of the equilibrium constant
  B) decreases the value of the equilibrium constant
  C) increase in the reactant production
  D) shift the equilibrium to the left
  Show Answer
  The correct answer is A .
• Question 52:

  CH_4(g) + Cl_2(g) → CH₃ Cl_(s) + HCl_(g)

  The major factor that influence the rate of the reaction above is

  Options:
  A) catalyst
  B) temperature
  C) concentration
  D) light
  Show Answer
  The correct answer is D .
• Question 53:

  

  The diagram above (Fig.3) shows the energy profile for the reaction A + B + = C + D From this diagram, it is clear that the reaction is

  Options:
  A) spontaneous
  B) isothermal
  C) adiabatic
  D) exothermic
  E) endothermic
  Show Answer
  The correct answer is D .
• Question 54:

  Aluminum hydroxide is used in the dyeing industry as a?

  Options:
  A) Dye
  B) Dispersant
  C) Salt
  D) Mordant
  Show Answer
  The correct answer is D .
• Question 55: Permanent hardness of water can be removed by Options:
  A) filtration
  B) adding slaked lime
  C) adding caustic soda
  D) boiling
  Show Answer
  The correct answer is C .
• Question 56: 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 57: The iron (III) oxide impurity in bauxite can be removed by? Options:
  A) Fractional crystallization in acid solution
  B) dissolution in sodium hydroxide and filtration
  C) extraction with concentrated ammonia and reprecipitation
  D) electroysis of molten mixture
  Show Answer
  The correct answer is B .
• Question 58: Which of the following compounds can be represented by the molecular formula C2 H6O? Options:
  A) propanal
  B) ethanol
  C) methanoic acid
  D) glucose
  Show Answer
  The correct answer is B .
• Question 59:

  The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;

  Options:
  A) saponification
  B) dehydration
  C) esterification
  D) hydrolysis
  Show Answer
  The correct answer is C .
• Question 60: How many unpaired electron are in the p-orbitals of a fluorine atom? Options:
  A) 3
  B) $0$
  C) 1
  D) 2
  Show Answer
  The correct answer is C .