In which of the substances, the formulas of which are SO2 and SO3, the mass fraction of sulfur is higher?

To solve this problem, we write down the given: SO2 and SO3
Find: in which of the compounds the mass fraction of sulfur is greater.
Decision:
Let’s write down the formula for finding the mass fraction:
w = n * Ar / Mr
Calculate the relative molecular weights of sulfur oxide (IV) and sulfur oxide (VI)
Mr (SO2) = 32 + 16 * 2 = 64
Mr (SO3) = 32 + 16 * 3 = 80
Calculate the mass fraction of sulfur in sulfur oxide (IV)
Let’s substitute the data into the formula:
w (S) = 32/64 = 0.5 or 50%
Calculate the mass fraction of sulfur in sulfur oxide (VI)
Let’s substitute the data into the formula:
w (S) = 32/80 = 0.4 or 40%
Answer: the mass fraction of sulfur is greater in the SO2 compound