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.
To calculate the mass of oxygen that combines with 1 mol of arsenic to form the oxide of arsenic (As2O3), you need to determine the molar ratio between arsenic and oxygen in the compound.
First, find the molar mass of As2O3 by summing the atomic masses of arsenic (As) and oxygen (O).
Molar mass of As = 74.92 g/mol
Molar mass of O = 16.00 g/mol
Molar mass of As2O3 = (2 × molar mass of As) + (3 × molar mass of O)
= (2 × 74.92 g/mol) + (3 × 16.00 g/mol)
= 149.84 g/mol + 48.00 g/mol
= 197.84 g/mol
The molar ratio between As and O in As2O3 is 2:3, meaning that for every 2 moles of arsenic, there are 3 moles of oxygen.
Now, calculate the mass of oxygen that combines with 1 mol of arsenic using the given mass of arsenic (0.702 g) and the molar ratio.
1 mol of As = 74.92 g
0.702 g of As = (0.702 g / 74.92 g/mol) mol
≈ 0.00936 mol
Using the molar ratio 2:3, we can find the moles of oxygen:
Moles of oxygen = (3/2) × moles of arsenic
= (3/2) × 0.00936 mol
= 0.0140 mol
Finally, convert the moles of oxygen to grams using the molar mass of O.
Mass of oxygen = moles of oxygen × molar mass of O
= 0.0140 mol × 16.00 g/mol
= 0.224 g
Therefore, the mass of oxygen that combines with 1 mol of arsenic to form As2O3 is approximately 0.224 g.
Regarding obtaining the empirical formula of the oxide, since the molecular formula of the compound given is already As2O3, it is also the empirical formula. The empirical formula represents the simplest whole-number ratio of atoms in a compound, which in this case is Arsenic:Oxygen = 2:3.