# Question #a4b0a

Jan 30, 2018

m=810g

#### Explanation:

Reaction:
${O}_{2} + 2 {H}_{2} \Rightarrow \textcolor{red}{2} {H}_{2} O$
If we got 22.5 moles of oxygen, we will have the doppel amount of water molecules, because of the $\textcolor{red}{2}$.
${n}_{{H}_{2} O} = 22.5 m o l \cdot 2 = 45 m o l$
$m = n \cdot M$
${M}_{{H}_{2} O} = 18 \frac{g}{m o l}$
${m}_{{H}_{2} O} = 45 \cancel{m o l} \cdot 18 \frac{g}{\cancel{m o l}} = 810 g$