Answer:
It will have no effect
Explanation:
The loss of tin oxide to evaporation will have no effect on the empirical formula of a compound.
The empirical formula of any compound is the simplest formula of that compound by which the combining atoms can be represented.
This formula is not affect by physical changes.
According to the law of constant composition "all pure samples of the same compound have the same element in the same proportion by mass".
Regardless of the mass loss or gain of any tin oxide compound, it will have the same empirical and molecular formula. The atoms are still combining in the ratio to give the product.