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 11: ${}_{88}^{226}Ra$ → ${}_{86}^{x}Rn$ + alpha particle Options:
  A) 226
  B) 220
  C) 227
  D) 222
  Show Answer
  The correct answer is D .
• Question 12:

  

  The compound above is

  Options:
  A) glycol
  B) primary alkanol
  C) secondary alkanol
  D) tertiary alkanol
  Show Answer
  The correct answer is C .
• Question 13: The reaction between hydrogen and iodine may be represented by the equation H₂(g)+ I₂(g) → 2HI(g), and is exothermic. Therefore Options:
  A) an increase in temperature favours the forword reaction
  B) an increase in pressure favours the backward reaction
  C) both pressure and temperature muct be increased to favour the forward reaction
  D) a decrease in temperature will favour the forward reaction
  E) a decrease in pressure and an increase in temperature will favour the forward reaction
  Show Answer
  The correct answer is D .
• Question 14: In the extraction of iron in the blast furnace, limestone is used to? Options:
  A) release CO₂ for the reaction
  B) reduce the iron ore
  C) increase the strenght of the iron
  D) remove impurities
  Show Answer
  The correct answer is D .
• Question 15: According to the kinetic theory an absence in temperature causes the kinetic energy of particles to Options:
  A) decrease
  B) increase
  C) remain constant
  D) be zero
  Show Answer
  The correct answer is C .
• Question 16: An example of an alcohol is Options:
  A) CCl₄
  B) CH₃COOH
  C) CHCl₃
  D) C₂H₆
  E) CH₃OH
  Show Answer
  The correct answer is E .
• Question 17:

  CH_4(g) + CI_2(g) $\to$ CH₂CI_(s) + HCI_g

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

  Options:
  A) Concentration
  B) Catalyst
  C) Temperature
  D) Light
  Show Answer
  The correct answer is D .
• Question 18: How many moles of oxygen molecules would be produced from the decomposition of 2.50 moles of potassium trioxochlorate (V)? Options:
  A) 2.50
  B) 3.50
  C) 3.75
  D) 7.50
  Show Answer
  The correct answer is C .
• Question 19: The colour of litmus in an alkaline medium is Options:
  A) Red
  B) Yellow
  C) Pink
  D) Blue
  Show Answer
  The correct answer is D .
• Question 20: When the two end alkyl groups ethyl ethanoate are interchange, the compound formed is known as Options:
  A) methyl ethanoate
  B) ethyl propanaote
  C) methyl propanoate
  D) propyl ethanoate
  Show Answer
  The correct answer is C .