Calculate the mass fraction of sulfur in the following compounds: H2S, H2SO3, H2SO4.

Let’s implement the solution:
1. Let’s calculate the relative molecular weight of inorganic compounds:
Mr (H2S) = 2 + 32 = 34;
Mr (H2SO3) = 2 + 32 + 16 * 3 = 82;
Mr (H2SO4) = 2 + 32 + 16 * 4 = 98.
2. Let’s calculate the share of sulfur:
W (S) = 32/34 * 100 = 94% (for H2S);
W (S) = 32/82 * 100 = 39% (H2SO3);
W (S) = 32/98 * 100 = 33% (H2SO4).
Answer: the mass fraction of sulfur for hydrogen sulfide acid is 94%, in sulfurous acid – 39%, in sulfuric acid – 33%.