Question

There are two binary compounds of mercury and oxygen. Heating either of them results in thedecomposition of the compound, with oxygen gas escaping into the atmosphere while leaving a residue of pure mercury. Heating 0.6498 g of one of the compounds leaves a residue of 0.6018 g. Heating 0.4172 g of the other compound results in a mass loss of 0.016 g. Determine the empirical formula of each compound.

Short answer

The empirical formula of two binary compounds are $HgO\&H{g}_{2}O$.

Step-by-step solution

Given Information

Mercury’s mass is 0.6018 g and oxygen’s mass can be found as,

$$\begin{gathered} =0.6498-0.6018 \\ =0.0480g \end{gathered}$$

Empirical formula for compound 1

The mole of Mercury can be denoted as,

$$\begin{gathered} =\frac{Mass}{Atomicmass} \\ =\frac{0.6018}{200.59} \\ =0.003molO \end{gathered}$$

On dividing mole value to get empirical formula,

$$\begin{gathered} \frac{0.003}{0.003}=1atomofHg \\ \frac{0.003}{0.003}=1atomofO \end{gathered}$$

The empirical formula of compound 1 can be found asHgO.

Empirical formula for compound 2

The mass of mercury can be found as,

$$\begin{gathered} =0.4172-0.016 \\ =0.4012g \end{gathered}$$

The oxygen’s mass can be denoted as 0.016 g.

The mole of Mercury can be denoted as,

$\begin{array}{rcl}& =& \frac{0.4012}{200.59}\\ & =& 0.002molO\\ O& =& \frac{0.016}{15.999}\\ & =& 0.001molO\end{array}$

On dividing mole value to get empirical formula,

$$\begin{gathered} \frac{0.002}{0.001}=2atomofHg \\ \frac{0.001}{0.001}=1atomofO \end{gathered}$$

The empirical formula of compound 2 can be found asHg₂O.