Calculate the mass of sulfur oxide 4 if it is known that during its catholic oxidation, sulfur oxide 6 with a mass of 14.4 g is formed

Calculate the mass of sulfur oxide 4 if it is known that during its catholic oxidation, sulfur oxide 6 with a mass of 14.4 g is formed, and the yield of the reaction product is 90% of the theoretically possible.

2SO2 + O2 = 2SO3
Let’s calculate the theoretically possible mass of sulfur trioxide:
mtheor (SO3) = 14.4 / 0.9 = 16 g;
Let’s find the amount of sulfur trioxide substance. According to the stoichiometry of the reaction, it will be equal to the amount of sulfur dioxide.
n (SO3) = n (SO2) = mtheor (SO3) / M (SO3) = 16/80 = 0.2 mol;
Find the mass of sulfur dioxide:
m (SO2) = n (SO2) * M (SO2) = 0.2 * 64 = 12.8 g.
Answer: m (SO2) = 12.8 g.