Chemistry - Mole Concept Question with Solution | TestHub

Ethanol is${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{O}\mathrm{H}$
Molecular mass$=12\times 2+6\times 1+16\times 1$
$=24+6+16=46$
Mass of carbon in ethanol$=12\times 2=24$
$\text{Mass}\text{\%}\text{of}\text{carbon}\text{=}\frac{\text{Mass}\text{of}\text{carbon}}{\text{Molar}\text{mass}\text{of}\text{compound}}\text{×}\text{100}$
$=\frac{24}{46}\times 100=52\mathrm{\%}$