In order to this question, we must write first the molar mass of C2S:
The molar mass = 56.08 g/mol (1 mol of C2S = 56.08 g)
We need to find how much 3 moles weigh out, let's proceed like this:
1 mol of C2S -------------------------- 56.08 g of C2S
3 moles of C2S -------------------------- X
X = 168.24 g
Answer: 168.24 g of C2S
