# How do you calculate the percentage by mass of carbon in carbon monoxide?

$\text{%C by mass}$ $=$ "Mass of carbon"/"Mass of carbon + oxygen"xx100%
$\text{So %C by mass}$ $=$ (12.011*g*mol^-1)/((12.011+15.999)*g*mol^-1)xx100%
So $C \equiv O$, percentage carbon by mass is a bit under 50%.