What is the empirical formula of an aluminum fluoride that is 32% by mass with respect to the metal?

1 Answer
Feb 16, 2017

We find an empirical formula of AlF_3..........

Explanation:

We assume 100*g of "aluminum fluoride". And we work out the molar quantities of each constituent, i.e.

"Moles of metal"=(32.0*g)/(27.0*g*mol^-1)=1.19*mol.

"Moles of fluorine"=(68.0*g)/(19.0*g*mol^-1)=3.58*mol.

We divide thru each molar quantity thru by the smaller molar quantity, that of aluminum to give:

Al:(1.19*mol)/(1.19*mol)=1; F:(3.58*mol)/(1.19*mol)=3, and thus we get an empirical formula of AlF_3.