# How do you find the percent composition of oxygen in sodium hydroxide?

Mar 21, 2017

The percent composition of oxygen in sodium hydroxide is 40.000%.

#### Explanation:

Determine the molar mass of sodium hydroxide $\left(\text{NaOH}\right)$. Then divide the molar mass of oxygen by the molar mass of $\text{NaOH}$, and multiply by 100.

Molar Masses

$\text{NaOH} :$$\text{39.997 g/mol}$
https://www.ncbi.nlm.nih.gov/pccompound?term=NaOH

$\text{O} :$$\text{15.999 g/mol}$ (periodic table)

Percent Composition of Oxygen

$\text{percent composition"=(15.999cancel("g"/"mol"))/(39.997cancel("g"/"mol"))xx100="40.000%}$