How many moles of water are needed to produce \( 50.7 \mathrm{~L} \) of oxygen gas according to the following reaction at \( 0{ }^{\circ} \mathrm{C} \) and \( 1 \mathrm{~atm} \) ?
\[
\text { water }(l) \rightarrow \text { hydrogen }(g)+\operatorname{oxygen}(g)
\]
Amount \( = \) \( \square \) moles