How to Prepare Solutions of a given Molarity:
Prepare 375mL of a 12M Ba(NO_3)_2 solution
Step 1) Determine the mass necessary of Ba(NO_3)_2
mols = Molarity * Volume
M=mols/volume
12M(0.375L)=4.5mols Ba(NO_3)_2
4.5mols Ba(NO_3)_2*(261.337g Ba(NO_3)_2/1mol Ba(NO_3)_2)= 1,176g
Step 2) Mix/Dissolving
In a volumetric flask or cylinder add the mass of solid and mix in a small amount of solvent to dissolve solid.
Step 3) Fill the flask or cylinder to the desired volume.
Step 4) Invert or gently shake flask solution to mix in the rest of the solvent.
Depending on types of solvents and solutes venting the flask may be necessary.