Question #2694b

1 Answer
Jun 17, 2017

The formula mass is 399.86 u.

Explanation:

The calculation might be easier if you first multiply all atoms inside the parentheses by the subscript 3.

Then Fe2(SO4)3 becomes Fe2S3O12.

Now, we can calculate the formula mass.

No.mAtommmArmmMass
l2mmmlFemml55.84mll111.68
l3mmmlSmmm32.06mm96.18
12mmmOmmll16.00mll192.00
mmmmmmmllTotal = 399.86

The formula mass is 399.86 u.