Question
What is the percentage of carbon, hydrogen and oxygen in ethanol?
Solution
Molecular formula of ethanol is C2H5OH.
Molar mass of ethanol (C2H5OH)
= 2(12.01) +6(1.008) +16.00 = 46.068g
Mass percentage of carbon
=
Mass percentage of hydrogen

Mass percentage of oxygen

Molar mass of ethanol (C2H5OH)
= 2(12.01) +6(1.008) +16.00 = 46.068g
Mass percentage of carbon
=

Mass percentage of hydrogen

Mass percentage of oxygen
