The percentage of elements

Exercise 1

Calculate the percentage of elements in methanol $CH_4O$ .

Molar mass = $M$ $=$ $12+4+16$ $=$ $32\frac{g}{mol}$ $\%_C$ $=$ $\frac{12\cdot 100}{32}$ $=$ $37.5 $ $\%_H$ $=$ $\frac{4\cdot 100}{32}$ $=$ $12.5 $ $\%_C$ $=$ $\frac{16\cdot 100}{32}$ $=$ $50.0 $