# Convert 345 moles of "H"_2"O" to molecules?

Feb 27, 2018

Using Avogadro's number, the total number of $\text{H"_2"O}$ molecules is $2.08 \cdot {10}^{26}$.

#### Explanation:

Avogadro's number relates the total amount of atoms/molecules contained in a mole of some element/compound:

$\text{1 mol element" = 6.022*10^23 " atoms}$

OR

$\text{1 mol compound" = 6.022*10^23 " molecules}$

We can then use stoichiometry to calculate the total number of molecules:

$\text{345 mol H"_2"O" * (6.022*10^23 "molecules H"_2"O")/("1 mol H"_2"O") = 2.08 *10^26 " molecules H"_2"O}$