1. The problem statement, all variables and given/known data 2. Relevant equations Law of multiple proportions 3. The attempt at a solution Carbon first: 4.61/0.39 = 11.82 C/H Hydrogen 0.39/4.61 = 0.08 H/C therefore 11.82/0.08 = 139.72 ~ 140 masses of carbon that combine with hydrogen are in a 140:1 ratio Does this look right? Or have i just done the second part? i have no idea what im doing Thanks for any help.