Solution Preparation and Dilution

      Chemicals are shipped around the world in their most concentrated forms. If they were not, we would be shipping lots of water along with the chemicals, which is less cost effective. 

      Sometimes we need to add some water to a solution to form a lower molarity solution.(or add more solute, to form a larger molarity solution.)

      The key idea is that the moles of solute is constant.

      General Form

                             M1L1=M2L2

                              moles solute before=moles solute after

       E.g

                    Minh has 3.00 L of 18.0 H2SO4. But teacher tells he to make 0.900L of 2.00M H2SO4. What should he do?

                    

                      Here is Minh's solution.

                       M1L1=M2L2

                     18.00M x L1= 0.900L X 2.00M

                                      L1=0.100L

                        0.900-0.100=0.800L of water

                       Minh just need to add 0.800L of water to the original solution and take out 0.900L of it.