# How do you find the elemental composition of carbon, hydrogen, and oxygen, of acetic acid?

Jun 24, 2017

We divide the mass of carbon by the mass of the molecule, and multiply by 100%.........

#### Explanation:

For ${H}_{3} C - C {H}_{2} O H$:

"% carbon"=(2xx12.011*g*mol^-1)/(46.07*g*mol^-1)xx100%=52.1%

"% hydrogen"=(6xx1.00794*g*mol^-1)/(46.07*g*mol^-1)xx100%=13.1%

"% oxygen"=(1xx15.999*g*mol^-1)/(46.07*g*mol^-1)xx100%=34.7%

Now %C and %H COULD be measured......(an analyst generally would not touch a liquid!). Oxygen content is a harder proposition, and generally when perform microanalysis on an organic sample we report %C, %H, and %N, the balance, i.e. the missing percentage that makes the sum of the other percentages 100% is assumed to be due to oxygen.