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 961: The relative atomic mass of a naturally occurring lithium consisting of 90% Li and 10% Li is Options:
  A) 6.9
  B) 7.1
  C) 6.2
  D) 6.8
  Show Answer
  The correct answer is C .
• Question 962:

  Consider the equation below:

  Cr${}_2$O${}_7^{2-}$ + 6Fe${}^{2+}$ + 14H${}^{+}$ $\to$ 2Cr${}^{3+}$ + 6Fe${}^{3+}$ + 7H${}_2$O.

  The oxidation number of chromium changes from

  Options:
  A) +5 to +3
  B) +6 to +3
  C) -2 to +3
  D) +7 to +3
  Show Answer
  The correct answer is B .
• Question 963: The production of ammonia by the haber process may be represented by the equilibrium equation N₂(g) + 3H₂(g) ↔ 2NH₃ ∆H = -22KJ. Therefore the production of ammonia will be favoured by? Options:
  A) only high pressure
  B) only high temperature
  C) a combination of high temperature and low pressure
  D) a combination of low temperature and high pressure
  E) low pressure
  Show Answer
  The correct answer is D .
• Question 964:

  The IUPAC name for CH${}_3$CH${}_2$COOCH${}_2$CH${}_3$ is

  Options:
  A) methylpropanoate
  B) ethylethanoate
  C) ethylpropanoate
  D) methylethanoate
  Show Answer
  The correct answer is C .
• Question 965: A hydrogen atom which has lost an electron contains Options:
  A) one proton only
  B) one neutron only
  C) one proton and one neutron
  D) one proton, one electron and one neutron
  Show Answer
  The correct answer is A .
• Question 966:

  The number of electrons in the valence shell of an element of atomic number 14 is?

  Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is D .
• Question 967:

  What volume of oxygen will remain after reacting 8cm of hydrogen gas with 20cm of oxygen gas

  Options:
  A) 10cm${}^3$
  B) 12cm${}^3$
  C) 14cm${}^3$
  D) 16cm${}^3$
  Show Answer
  The correct answer is D .
• Question 968: Which of the following is used as fuel in miners' lamp? Options:
  A) Ethanal
  B) Ethyne
  C) Ethene
  D) Ethane
  Show Answer
  The correct answer is B .
• Question 969:

  3Cu + pHNO₃ →3Cu(NO)₂ + 4H₂ O + xNO

  In the equation above, the values of p and x respectively are

  Options:
  A) 1 and 3
  B) 2 and 3
  C) 6 and 2
  D) 8 and 2
  Show Answer
  The correct answer is D .
• Question 970: Electronic configuration of an elements 13x in the subsidiary energy level is Options:
  A) $1s^{2}2s^{2}2p^{6}3s^{2}3p^1$
  B) $1s^{2}2s^{2}2p^{4}3p^{1}3s^1$
  C) $1s^{2}2s^{2}2p^{6}3s^{2}3p^3$
  D) $1s^{1}2s^{2}2p^{6}3s^{2}3p^4$
  Show Answer
  The correct answer is A .