# Molecular formula

posted by
**Mac**
.

I have to find the molecular formula for As2O3, to do so I have to divide its molecular mass by its empirical mass. I have worked ou that its molecular mass is 197.9 g/mol. How would I find its empirical mass, is it not the same as its molecular mass? Many thanks

I have 197.84. If the molar mass is 197.84, then the empirical mass is the same since As2O3 is already in its simplest form.

Excellent, many thanks for your help.