Step 1 calculate the mass of Carbon in CO2
CO2 = 0.01962 moles
There is 1 mole of C in CO2
And if hydrocarbon completely burns and all the C from the compound becomes CO2
Hence moles of C in the hydrocarbon compound = 0.01962 moles
mass of C = 0.01962 mol x 12 g/ mol = 0.23577 g
Step 2 calculate the mass of Hydrogen in H2O
Given H2O = 0.01961moles
There are 2 moles of H in H2O
so moles of H in the compound = 0.03922 moles
mass of H = 0.03922moles x 1.008g/mol = 0.039530 g
Step 3 calculate the mass of O
mass O = Total mass of simple compound – sum of masses of C and H
Total mass of H + C = 0.27530 g
Given mass of sample = 0.4647 g
mass of O = (0.4647 g - 0.27530 g) = 0.18940 g
moles of O = 0.18940 g /16 g/mol = 0.01183 moles
Step 4 calculate molar ratio
Molar ratio of all the elements (H , C,and O) in the compound
molar ratio of C : H : O = 0.01962 : 0.03922 : 0.01183
smallest number 0.01183
divide the ratio by the smallest number
molar ratio of C : H : O = 1.657 : 3.313 : 1.000
Moltiply with 3 to get simplest whole number ratio
Final ratio = C : H : O = 5 : 10 : 3
Hence Empirical formula C5H10O3
