Question

Styrene has the empirical formula `CH`. It has a molar mass of 104 g. What is the multiplier to get the molecular formula?

Answer 1

The molecular formula is always a whole number multiple of the empirical formula. Of course, the multiple might be `1`.

Explanation:

Given what I have said:

`("Empirical formula")xxn="Molecular formula"`

`(CH)xxn=104*g*mol^-1`

`(12.01+1.01)*g*mol^-1xxn=104*g*mol^-1`

Clearly, `n=8`, and the molecular formula is `C_8H_8`.

Of course this is reasonable inasmuch that we know that the styrene monomer is `C_6H_5CH=CH_2`, i.e. vinyl benzene.