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 1201: An oxide XO₂ has a vapour density of 32. What is the atomic mass of X? Options:
  A) 20
  B) 32
  C) 14
  D) 12
  Show Answer
  The correct answer is B .
• Question 1202: One mole of hydrocarbon contains 6g of hydrogen. If the molecular weight is 54, the hydrocarbon is an? Options:
  A) alkanone
  B) alkane
  C) alkene
  D) alkyne
  Show Answer
  The correct answer is D .
• Question 1203:

  8g CH₄ occupies 11.2 dm³ at s.t.p. What volume would 22 g of CH₃CH₃ occupy under the same condition?

  (C = 12, H = 1)

  Options:
  A) 3.7 dm³
  B) 11.2 dm³
  C) 22.4 dm³
  D) 33.6 dm³
  Show Answer
  The correct answer is B .
• Question 1204:

  

  2-methylbut-2-ene has the structure

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is D .
• Question 1205: The partial pressure of oxygen in a sample of air is 452mmHg and the total pressure is 780mmHg. What is the mole fraction of oxygen? Options:
  A) 0.203
  B) 0.579
  C) 2.060
  D) 5.790
  Show Answer
  The correct answer is B .
• Question 1206: Cathode rays cause an object placed behind a perforated anode to cast a shadow on the screen. This observation shows that the rays Options:
  A) are positively charged
  B) are negatively charged
  C) Have mass
  D) travel in straight lines
  Show Answer
  The correct answer is D .
• Question 1207:

  

  The diagram above best illustrates the effect of decrease in

  Options:
  A) concentration
  B) temperature
  C) surface area
  D) pressure
  Show Answer
  The correct answer is A .
• Question 1208:

  MnO₂ + 2CI^- + 4H⁺ → MnO²⁺ + CI₂ + 2H₂O.

  The changes is oxidation numbers when the manganese, chloride and hydrogen ions react according to the above equation are respectively?

  Options:
  A) 2, 2, 4
  B) -1, -2, 4
  C) -2, 1, 0
  D) 2, 4, 0
  Show Answer
  The correct answer is C .
• Question 1209:

  The Sulphide which is insoluble in dilute hydrochloric acid is

  Options:
  A) FeS
  B) CuS
  C) ZnS
  D) Na2S
  Show Answer
  The correct answer is B .
• Question 1210: Which of the following is acceptable as the organic product of the reaction of ethanoic acid and ethanol with an acid catalyst? Options:
  A) Ethyl ethanoate
  B) Methyl ethanoate
  C) Ethyl methyl ketone
  D) Butanol
  E) None
  Show Answer
  The correct answer is A .