Question

compound 1 contains 15.0g of hydrogen and 120.0g oxygen. What is the percent compound of each element?

Answer 1

Note down the formula below

$\boxed{\sf Mass\%\;of\; element=\dfrac{Mass\:of\:the\: element}{Mass\;of\:the\: compound}\times 100}$

Mass of the compound

$\\ \sf\longmapsto 15+120=135g$

Mass % of Hydrogen:-

$\\ \sf\longmapsto \dfrac{15}{135}\times 100$

$\\ \sf\longmapsto \dfrac{1}{9}\times 100$

$\\ \sf\longmapsto 11.1\%$

Mass % of Oxygen:-

$\\ \sf\longmapsto \dfrac{120}{135}\times 100$

$\\ \sf\longmapsto \dfrac{8}{9}\times 100$

$\\ \sf\longmapsto 88.9\%$