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 1: When salt loses its water of crystallization to the atmosphere on exposure, the process is said to be Options:
  A) efflorescence
  B) déliquescence
  C) effervescence
  D) fluorescence
  Show Answer
  The correct answer is A .
• Question 2: The shape of ammonia molecules is Options:
  A) trigonal planar
  B) octahedral
  C) square planar
  D) tetrahedral
  Show Answer
  The correct answer is A .
• Question 3:

  Which important nitrogen-containing compound is produced in Haber's process?

  Options:
  A) NH${}_3$
  B) NO${}_2$
  C) NO
  D) HNO${}_3$
  Show Answer
  The correct answer is A .
• Question 4: The normal boiling point of a liquid is defined as Options:
  A) the temperature at which its vapour pressure equals the atmospheric pressure
  B) the temperature at which bubbles begin to form
  C) the temperature at which the vapour pressure equals 1 temperature
  D) the temperature at which the rate of condensation of vapour equals the rate of vaporisation of the liquid
  E) the temperature at which the space above the liquid is saturated
  Show Answer
  The correct answer is C .
• Question 5:

  Which of the following could not be alkane?

  Options:
  A) C${}_4$H${}_{10}$
  B) C${}_5$H${}_{12}$
  C) C${}_7$H${}_{14}$
  D) C${}_8$H${}_{18}$
  Show Answer
  The correct answer is C .
• Question 6: A sample of orange juice is found to have a pH of 3.80. What is he concentration of the hydroxide ion in the juice? Options:
  A) 1.6 x 10^-4
  B) 6.3 x 10^-11
  C) 6.3 x 10^-4
  D) 1.6 x 10^-11
  Show Answer
  The correct answer is B .
• Question 7: The atomic number of caesium is 55 and its atomic mass is 133. The nucleus of caesium atom therefore contains Options:
  A) 78 protons and 55 elections
  B) 55 protons and 78 neutrons
  C) 55 neutrons 78 electrons
  D) 78 protons and 55 neutrons
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  The correct answer is B .
• Question 8:

  Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,

  Options:
  A) P will form an electrovalent bond with R
  B) Q will form a covalent bond with S
  C) R will form an electrovalent bond with S
  D) Q will form an electrovalent bond with S
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  The correct answer is D .
• Question 9: Which of the following statements is true about 2-methylpropane and butane Options:
  A) They are members of the same homologous series
  B) They have the same boiling point
  C) They have different number of carbon atoms
  D) They have the same chemical properties
  Show Answer
  The correct answer is A .
• Question 10: The basicity of CH₃COOH is Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is A .