1.a compound was found to contain 43.66% phosphorus and the rest was oxygen.find the simpliest formular of the compound?

1 Answer
Mar 19, 2018

We gots #P_2O_5# as the empirical formula...

Explanation:

With all these problems, it is useful to assume an #100*g# mass of compound, and proceed from here to the empirical formula, the which is the simplest whole number ratio defining constituent atoms in a species...

#"Moles of phosphorus"=(43.66*g)/(31.00*g*mol^-1)-=1.408*mol#

#"Moles of oxygen"=((100-43.66)*g)/(16.00*g*mol^-1)-=3.521*mol#...

In each case we divided the elemental mass by the ATOMIC mass of each element... From where did I get these atomic masses?

And we divide thru by the lowest molar quantity to get an empirical formula of #P_((1.408*mol)/(1.408*mol))O_((3.521*mol)/(1.408*mol))=PO_(2.50)#...

But we requires WHOLE numbers...and so we got #2xxPO_(2.50)=P_2O_5#....

The actual material is likely #P_4O_10#...but the given data do not allow us to make this formulation....