# How many water molecules are in 39 formula units of calcium chloride dihydrate?

Apr 9, 2017

78

#### Explanation:

di = 2

So, in each formula unit of calcium chloride dihydrate,
$C a C {l}_{2.} 2 {H}_{2} O$, there are two water molecules.

Multiply 39 formula units x 2 water molecules per formula unit.

$\text{39 formula units" xx ("2 water molecules")/("1 formula unit") = "78 water molecules}$#