What is the mass sulfur and the percentage?

Question

A manufacturer begins with 10.00 kg of cinnabar and produces 8.62 kg of elemental mercury. What was the mass of sulfur in the original cinnabar?

1. Mass of sulfur: ? kg

Express the mass of sulfur in cinnabar as a percentage.

1. percent sulfur in cinnabar: ? %

Answer 1

Cinnabar = HgS

mass of Hg = 8.62 kg

mass of S = 10.00 kg - 8.62 kg = 1.38 kg

Mass % of S = 1.38 kg / 10.00 kg (x100%) = 13.8% S