Question

1) 65. mLs of water is added to 403 mLs of 2.39 M solution of HCl. What is the new molarity of the solution?

2) How much water must be added to 403mLs pf 2.39 M solution of HCl. What is the new molarity of the solution?

Answer 1

(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'

                                              = ( 2.39x403) / 468

                                              = 2.06 M

Therefore the molarity of new solution is 2.06 M

(2)Question (2) is not clear.