(1) According to law of dilution  MV = M'V'
Where M = Molarity of stock = 2.39 M
V = Volume of the stock = 403 mL
M' = Molarity of dilute solution = ?
V' = Volume of the dilute solution = 403+65(from water) = 468
mL
Plug the values we get  , M' = MV /V'
                                            Â
= ( 2.39x403) / 468
                                            Â
= 2.06 M
Therefore the molarity of new solution is 2.06 M
(2)Question (2) is not clear.
