Question

Show the calculation of the molality of a solution made by dissolving 15.9 grams of Ca3(PO4)2 in 400 grams of water.

Answer 1

The molality of a solution : 0.128 m

Further explanation

Given

15.9 g of Ca3(PO4)2 in 400 grams of water.

Required

The molality

Solution

molality = mol solute / kg solvent

solute= Ca3(PO4)2(MW=Molecular Weight: 310.2 g/mol)

mol solute :

`\tt (15.9)/(310.2)=0.0512`

The molality :

`\tt (0.0512)/(0.4~kg)=0.128~m`