What is the empirical formula of a phosphoric acid that contains 0.3086 g of hydrogen, 3.161 g of phosphorus, and 6.531 g of oxygen?

1 Answer
Apr 29, 2016

H2 P4 O1

Explanation:

In order to calculate the Empirical formula , we will assume that we have started with 10 g of the compound. On decomposition , we obtained 0.3086 g of Hydrogen , 3.161 g of Phosphorus, and 6.531 g of Oxygen.

*Step 1* Calculating the number of moles of different elements

nH= mass of H/ molar mass of H

nH= 0.3086 g / 1 g mol1

nH= 0.3086 mol

nP = mass of P/ molar mass of P

nP=3.161g31gmol^(-1)#

nP= 1.02 mole

nO = mass of O / molar mass of O

nO= 6.531 g / 32 g mol1

nO= 0.2 mol

Calculating the Simple Ratio of the moles

H= 0.3806/ 0.2 =4 , P = 1.02 / 0.2 =5 , O= 0.2/0.2 =1

H2 P4 O1