# Calculating molarity and molality.

Senza33
Thu, 01/11/2018 - 18:51

A sample of potassium aluminum sulfate 12-hydrate, KAl(SO4)2.12H2O, containing 118.6 mg is dissolved in 1.000 L of solution. Calculate the following for the solution:

a. The molarity of KAl(SO4)2.

b. The molarity of (SO4)2

c. The molality of KAl(SO4)2, assuming that the density of the solution is 1.00 g/mL.

I know how to obtain molarity and molarity from simple solutions, but I have no idea how to deal with a compound like this. What is KAI and how would I obtain it's molar mass? Also, how would I go about deducing (SO4)2 from the whole compound. Help much appreciated with all the steps.