To determine the empirical formula of the compound given, we need to determine the ratio of each element in the compound. To do that we assume to have 100 grams sample of the compound with the given composition. Then, we calculate for the number of moles of each element. We do as follows:
mass moles
Sn 78.77 0.6636
O 21.23 1.3269
Dividing the number of moles of each element with the smallest value, we will have the empirical formula:
moles ratio
Sn 0.6636 0.6636/0.6636 = 1
O 1.3269 1.3269/0.6636 = 2
The empirical formula would be SnO2.
