How much oxygen can be obtained by decomposition of mercury (II) oxide with an amount of 0.2 mol?

Let’s carry out the solution, write down the reaction equation:
2HgO = 2Hg + O2 – the decomposition reaction of mercury oxide, oxygen and mercury are released;
Let’s make calculations using the formulas:
M (HgO) = 200.5 + 16 = 216.5 g / mol;
M (O2) = 16 * 2 = 32 g / mol;
Let’s make a proportion according to the equation:
0.2 mol (HgO) – X mol (O2);
-2 mol               -1 mol hence, X mol (O2) = 0.2 * 1/1 = 0.2 mol;
Let’s calculate the volume of oxygen according to Avogadro’s law:
V (O2) = 0.1 * 22.4 = 2.24 liters.
Answer: during the decomposition of mercury oxide, oxygen was released in a volume of 2.24 liters.