The empirical formula of the compound is therefore P1O2.5, which can be simplified to P2O5 by multiplying all the subscripts by 2. Thus, the empirical formula of the compound is P2O5.
Brief description about this formula
To determine the empirical formula of a compound, we need to find the relative number of atoms of each element present in the compound. We can do this by assuming a 100 g sample of the compound, which means that:
- The sample contains 43.64 g P (0.4364 x 100 g)
- The sample contains 56.36 g O (0.5636 x 100 g)
Next, we need to convert the masses of each element to moles. To do this, we divide the mass of each element by its molar mass:
- Moles of P = 43.64 g / 30.97 g/mol = 1.408 mol
- Moles of O = 56.36 g / 15.99 g/mol = 3.523 mol
We can then divide the number of moles of each element by the smallest number of moles to obtain the empirical formula. In this case, the smallest number of moles is 1.408 mol, so we divide each number of moles by 1.408:
- Moles of P in empirical formula = 1.408 mol / 1.408 mol = 1.000
- Moles of O in empirical formula = 3.523 mol / 1.408 mol = 2.500