The empirical formula of the compound is calculated as follows:
Given that
It contains 85.63% carbon, and 100-85.63= 14.37 % hydrogen
now assume that the amount of compound is100 g thus there is 85.63 g C and 14.37 g H
NOW divide these percentages by the molar mass of the elements to get a number of moles for each substance.
NUMBER OF MOLES = AMOUNT IN G / MOLAR MASS
Carbon: 85.63/12 = 7.1
Hydrogen: 14.37/1 = 14.3
Now arrange these in a ratio as follows:
C:H
7.1/7.1 :14.3/7.1
1:2
divide through by the smallest number
Therefore, the empirical formula is CH2
Then calculate the molar mass of that molecule:
(1x12) + (2x1) = 14
Here the molar mass of compound is 56.10 g/mol
Since, 14 goes into 56.10 g/mol 4 times thus the molecular formula is : C4H8