Question

A sample of a compound contains 3.21 g of sulfur and 11.4 g of fluorine. Which of the following represents the empirical formula of the compound?

A.SF2

B.SF3

C.SF4

D.SF5

E.SF6

Answer 1

Answer: The empirical formula will be
`SF_6`

Step-by-step explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of S= 3.21 g

Mass of F = 11.4 g

Step 1 : convert given masses into moles.

Moles of S =
`\frac{\text{ given mass of S}}{\text{ molar mass of S}}= (3.21g)/(32g/mole)=0.1moles`

Moles of F =

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For S=
`(0.1)/(0.1)=1`

For F =
`(0.6)/(0.1)=6`

The ratio of S: F= 1: 6

Hence the empirical formula is
`SF_6`