Question

How many grams of chromium are there in 85g of C2S3

Answer 1

$120g \: of \: c2s3 \: = 24g \: of \: c \\ 85g \: of \: c2s3 \: \: = \frac{24}{120} \times 85 \:g \: of \: c \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = \: 19g \: of \: c$

Answer 2

Mass of Chromium = 52u
Mass of Sulphur = 32u

Upon Calculation, you will find that in 80g of Cr2S3 [Chromium(III) sulfide], there is 41.6g of Cr.

CalculationMass of Chromium = 52u
Mass of Sulphur = 32u

Mass of Cr2 = 104u
Mass of S3 = 96u
Total Mass = 200u 

Mass of Cr/Total mass = 104/200 = 0.52
Now multiply it by 80, you get 41.6

So if you take in grams its 41.6g out of 80g.