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 1931:

  

  Which of the curves in the above graph illustrates the behaviour of an ideal gas?

  Options:
  A) W
  B) X
  C) Y
  D) Z
  Show Answer
  The correct answer is C .
• Question 1932:

  Equal volumes of CO,SO₂, and H₂S were released into a room at the same point and time. Which of the following gives the order of diffusion of the gases to the opposite corner of the room?

  (S = 32, C = 12, O = 16, N = 14, H = 1)

  Options:
  A) CO, SO₂,NO₂,H₂S
  B) SO₂,NO₂,H₂S,CO
  C) CO,H₂S,SO₂,NO₂
  D) CO,H₂S,NO₂,SO₂
  Show Answer
  The correct answer is D .
• Question 1933: 10.0 dm³ of water was added to 2.0 mol dm^-3 of 2.5dm³ solution of HCl. What is the concentration of the final solution in mol dm^-3? Options:
  A) 0.4
  B) 8.0
  C) 2.0
  D) 0.5
  Show Answer
  The correct answer is A .
• Question 1934: Pure solvents are obtained by Options:
  A) distillation
  B) condensation
  C) extraction
  D) evaporation
  E) desolution
  Show Answer
  The correct answer is A .
• Question 1935: A certain volume of gas at 298k is heated such that its volume and pressure are now four times the original values. What is the new temperature? Options:
  A) 18.6k
  B) 100.0k
  C) 298.0k
  D) 1192.0k
  E) 4768.0k
  Show Answer
  The correct answer is E .
• Question 1936:

  The oxidation state(s) of nitrogen in ammonium nitrite is/are

  Options:
  A) -3, +3
  B) +5
  C) -3, +5
  D) -3
  Show Answer
  The correct answer is A .
• Question 1937:

  When the end alkyl groups of ethyl ethanoate are interchanged, the compound formed is

  Options:
  A) propylmethanoate
  B) ethylpropanoate
  C) methyl ethanoate
  D) methyl propanoate
  Show Answer
  The correct answer is B .
• Question 1938: The solubility curve shows the variation of solute concentration with Options:
  A) volume
  B) temperature
  C) vapour
  D) pressure
  E) weight
  Show Answer
  The correct answer is A .
• Question 1939: 30 cm³ of 0.1 M Al (NO₃)₃ SOLUTION IS RECTED WITH 100cm³ of 0.15M of NaOH solution. Which reactant is in excess, and by now much ? Options:
  A) NaOH solution by 70 cm³
  B) NaOH solution, by 60 cm³
  C) NaOH solution by 40 cm³
  D) Al(NO₃)₃ solution by 20 cm³
  E) Al(NO₃)₃ solution by 10 cm³
  Show Answer
  The correct answer is C .
• Question 1940:

  A sample of any of the following substances disappearsafter some time when exposed to air like camphor, naphthalene, or dry ice. This phenomenon is called?

  Options:
  A) Sublimation
  B) Evaporation
  C) Diffusion
  D) Radiation
  Show Answer
  The correct answer is A .