M = 58 g m o l C n H 2 n + 1 O H {\displaystyle M=58{\frac {g}{mol}}\qquad C_{n}H_{2n+1}OH} n = ? {\displaystyle n=?\!}
M = n M C + ( n + 2 ) M H + M O {\displaystyle M=n\ M_{C}+(n+2)\ M_{H}+M_{O}} n = M − ( 2 M H + M O ) M C + M H {\displaystyle n={\frac {M-(2M_{H}+M_{O})}{M_{C}+M_{H}}}} n ≈ 3 {\displaystyle n\approx 3\!} W % 1 = ? C H 4 {\displaystyle W_{\%1}=?\qquad CH_{4}} W % 2 = ? C 3 H 8 {\displaystyle W_{\%2}=?\qquad C_{3}H_{8}}