1. Bestem den molære masse for hvert element:
* Carbon (c):12,01 g/mol
* Hydrogen (H):1,01 g/mol
* Oxygen (O):16,00 g/mol
2. Beregn den molære masse af hele molekylet:
* CH3CH2OH:(2 x 12,01) + (6 x 1,01) + 16,00 =46,07 g/mol
3. Beregn masseprocenten for hvert element:
* carbon (c): [(2 x 12,01) / 46,07] x 100% = 52,14%
* brint (H): [(6 x 1,01) / 46,07] x 100% = 13,13%
* ilt (O): [16.00 / 46.07] x 100% = 34,73%
Derfor er den procentvise sammensætning af CH3CH2OH:
* kulstof:52,14%
* brint:13,13%
* ilt:34,73%