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 2191: 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 2192: The volume occupies by 1.58g of a gas at s.t.p is 500cm³. What is the relative molecular mass of the gas? (G.M.V at s.t.p = 22.40dm³) Options:
  A) 28
  B) 32
  C) 44
  D) 71
  Show Answer
  The correct answer is D .
• Question 2193: The scale of a chemical balance is made of iron plate and coated with copper electrolytically because Options:
  A) iron is less susceptible to corrosion than copper
  B) copper is twice as less susceptitible to corrosion as iron
  C) copper is less susceptible to corrosion than iron
  D) copper and iron are equally susceptible to corrosion
  Show Answer
  The correct answer is C .
• Question 2194:

  

  Which of the following functional groups will give gas bubbles when treated with a saturated solution of sodium hydrogen trioxocarbonate (IV)?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .
• Question 2195:

  

  Use the diagram above to answer this question. The activation energy of the uncatalysed reaction is

  Options:
  A) X
  B) X + Y
  C) X - Y
  D) Y
  Show Answer
  The correct answer is A .
• Question 2196:

  What is the sum of the oxidation numbers in a neutral compound?

  Options:
  A) +2
  B) -1
  C) 0
  D) +1
  Show Answer
  The correct answer is C .
• Question 2197: The commonest feature of reactions at the anode is that Options:
  A) electrons are consumed
  B) oxidation is involved
  C) ions are reduced
  D) electrode dissolves
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  The correct answer is B .
• Question 2198: Nuclear fission involves the splitting of a heavy element into two nuclei of Options:
  A) nearly equal masses with a relaese of energy and radiaton
  B) equal masses with a relaese of energy
  C) equal masses with a release of energy and radiation
  D) unequal masses without any relaese of energy
  Show Answer
  The correct answer is A .
• Question 2199: Hypochlorous acid is used as a bleach because Options:
  A) it is a strong acid
  B) it yields chlorine readily in pure water
  C) it is an oxidising agent
  D) it is a weak acid
  E) it is a reducing agent
  Show Answer
  The correct answer is C .
• Question 2200:

  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 .