How much oxygen will be released as a result of the decomposition of 43.4 g of HgO?

Let us write the equation for the decomposition of mercury oxide:
2HgO = 2Hg + O2 – oxygen is formed;

Calculations according to the formulas of substances:
M (HgO) = 200.5 g / mol;

M (O2) = 32 g / mol.

Determine the amount of the original substance:
Y (HgO) = m / M = 43.4 / 200.5 = 0.2 mol.

Proportion:
0.2 mol (HgO) – X mol (O2);

-2 mol – 1 mol from here, X mol (O2) = 0.2 * 1/2 = 0.1 mol.

We find the volume of O2:
V (O2) = 0.1 * 22.4 = 2.24 L

Answer: we received oxygen in a volume of 2.24 liters.