posted by bex .
I have a chemical composition of As2O3. How do I calculate the mass of oxygen that combines with 1 mol of arsenic to form the oxide of arsenic?
How do I use this to obtain the empirical formula of the oxide?
That IS the empirical formula of the compound. You calculated the mass of one that combined with the other to obtain the empirical formula--at least I suppose that is where the percents came from.
I have a mass of 0.225g of oxygen reaecting with 0.702g of arsenic to make the compound.
Does 0.702g = 1 mol?
No, 1 mol, of course, is not 0.702 g. One mol As is 74.92 g. Calculate the grams of oxygen that will combine with 74.92 g As to form As2O3.