# What is the formula mass of water?

Jun 9, 2016

$18.017 \text{ g/mol H"_2"O}$

#### Explanation:

Two hydrogen atoms each with an atomic mass of $1.008 \text{ g/mol}$

Plus

One oxygen atom with an atomic mass of $15.999 \text{ g/mol}$

(2×1.008)+15.999=18.017" g/mol"