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 551: Which of the following statements is true about 2-methylpropane and butane Options:
  A) They have different number of carbon atoms
  B) They are members of same homologous series
  C) They have the same boiling points
  D) They have the same chemical properties
  Show Answer
  The correct answer is D .
• Question 552:

  What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution?

  [ F = 96 5000 C mol^-1 ]

  Options:
  A) 24 125 coulombs
  B) 48 250 coulombs
  C) 72 375 coulombs
  D) 96 500 coulombs
  Show Answer
  The correct answer is B .
• Question 553:

  The hybridization in the compound $C{H}_3-C{H}_2-C\equiv H$ is

  Options:
  A) sp${}^3$ and sp
  B) sp
  C) sp${}^2$
  D) sp${}^3$ and sp${}^2$
  Show Answer
  The correct answer is A .
• Question 554: Alloys are best prepared by Options:
  A) electroplating
  B) Arc-welding
  C) reducing and mixture of their metallic
  D) cooking a molten of the metals
  Show Answer
  The correct answer is D .
• Question 555: The number of electronic shells contained in an atom with electron configuration 1s²2s²2p⁶3s²3p⁶4s² is Options:
  A) 3
  B) 2
  C) 4
  D) 5
  Show Answer
  The correct answer is C .
• Question 556:

  N${}_2$O${}_4$⇔ 2NO${}_2$ ( = -ve)

  From the reaction above, which of these conditions would produce the highest equilibrium yield forN${}_2$O${}_4$?

  Options:
  A) Low temperature and high pressure
  B) Low temperature and low pressure
  C) high temperature and low pressure
  D) high temperature and high pressure
  Show Answer
  The correct answer is A .
• Question 557: Which of the following methods can be used to obtain pure water from a mixture of sand, water and methanoic acid? Options:
  A) netralization with NaOHfoolowed by filtration
  B) neutralization with NaOH followed by distillation
  C) fractional distillation
  D) filtration followed by distillation
  Show Answer
  The correct answer is D .
• Question 558: Which of the following is NOT a true statement of the kinetic Theory of Gases? Options:
  A) The molecules move at random
  B) The size of molecules is negligble as compared with the volume of gas
  C) The molecular collisions are perfectly elastic
  D) Every molecule has the same kinetic energy at a particular temperature
  E) The average kinetic energy is proportional to the absolute temperature of the gas
  Show Answer
  The correct answer is D .
• Question 559: An oxide XO₂ has a vapour density of 32. What is the atomic mass of X? Options:
  A) 32
  B) 20
  C) 14
  D) 12
  Show Answer
  The correct answer is A .
• Question 560: An emulsion paint consists of ? Options:
  A) gas or liquid particles dispersed in liguid
  B) liquid particles dispersed in liquid
  C) solid particles dispersed in liquid
  D) solid particles dispersed in solid
  Show Answer
  The correct answer is B .