Question

A Sample was analyzed and shown to have 63.52% iron and 36.48% sulfur. Determine the empirical formula?

Answer 1

empirical formula: FeS

Explanation:

Given: sample 63.52% iron (Fe), 36.48% sulfur (S)

Assume there is 100 g of the unknown sample. This means:
`63.52" g Fe"; " "36.48" g S"`

Calculate molar mass of each substance:

`63.52 "g Fe" xx (1 " mol Fe")/( 55.845 " g Fe") ~~ 1.137 " mol Fe"`

`36.48 "g S" xx (1 " mol S")/( 32.06 " g S") ~~ 1.138 " mol S"`

Since the number of moles is approximately the same, the ratio of elements is 1:1.

The empirical formula: FeS