# How many hydrogen atoms in a 15*mol quantity of water?

$30 \times {N}_{A}$, where ${N}_{A} = \text{Avogadro's Number.........}$
We could have equally asked how many hydrogen atoms are there in the $\text{ONE molecule of water?}$ Of course there are 2.
The mole is simply another number, admittedly a very large number, i.e. ${N}_{A} = 6.022 \times {10}^{23} \cdot m o {l}^{-} 1$.
And thus in a $15 \cdot m o l$ quantity there are approx. $9 \times {10}^{24}$ $\text{hydrogen atoms}$. What is the mass of this number of $\text{hydrogen atoms}$?