# Question #9885a

Aug 10, 2017

18 grams

#### Explanation:

$6.02 \times {10}^{23}$ molecules equal a mole of molecules.

${H}_{2} O$ water has a molar mass of 18 grams

$2 \times H = 2 \times 1 = 2$ grams for Hydrogen

$1 \times O = 1 \times 16 = 16$ grams for Oxygen

$2 + 16 = 18$ grams total for Water ${H}_{2} O$

A mole of water has a mass of 18 grams. so Avogardo's number of molecules = a mole = 18 grams.