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

1 Answer

78

Explanation:

di = 2

So, in each formula unit of calcium chloride dihydrate,
# CaCl_2. 2H_2O#, there are two water molecules.

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

# "39 formula units" xx ("2 water molecules")/("1 formula unit") = "78 water molecules"##