Question

What is the Mass per cent of oxygen in ethanol

Answer 1

Answer:-

Molecular Mass of Ethanol:-

$\\ \sf\longmapsto C_2H_5OH$

$\\ \sf\longmapsto 2(12u)+5(1u)+16u+1u$

$\\ \sf\longmapsto 24u+5u+17u$

$\\ \sf\longmapsto 29u+17u$

$\\ \sf\longmapsto 46u$

Atomic Mass of oxygen =16u

We know that

$\boxed{\sf Mass\% \:of\:x=\dfrac{Mass\:of\:the\:element\;in\:compound}{Molecular\:Mass\:of\:compound}}$

$\\ \sf\longmapsto Mass\%\:of\:O_2=\dfrac{16}{46}\times 100$

$\\ \sf\longmapsto Mass\%\:of\:O_2=\dfrac{1600}{46}$

$\\ \sf\longmapsto Mass\%\:of\:O_2=34.9\%$