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JAMB Chemistry 1980 Question 5

Question 5

Chemical Formulae and Equations

A sample of an oxide of mercury weighed 1.00 g. When this was heated, oxygen was given off, and 1.00 g of mercury metal only was left. What is the formula of the oxide? (Hg = 200, O = 16)

  1. A.Hg2O
  2. B.HgO2
  3. C.HgO4
  4. D.HgO
  5. E.None of the above.
Show the answer and explanation

Answer: E (None of the above.)

Explanation

As printed, the mass does not change, so no oxygen is accounted for and none of the formulae can be worked out from the data. (Any real mercury oxide would leave less than 1.00 g of mercury.)