Question

When 2.5000 g of an oxide of mercury, (HgxOy) is decomposed into the elements by heating, 2.405 g of mercury are produced. Calculate the empirical formula.

Answer 1

In the given question,

HgxOy (2.50 g) = xHg (2.405 g) + yO

Here, mass of oxygen = 2.50 - 2.405

= 0.095 g

The moles of O₂ = 0.095 / 16 = 0.00594 moles

Moles of Hg = 2.405 / 200.60 = 0.01198 moles

Thus, the ratio of Hg : O is,

0.00594 : 0.01198 or 1 : 2

As the ratio is 1 : 2, thus, the empirical formula is Hg₂O