Question

How many mL of water must be added to 200 mL of .65 M HCL to dilute the solution to .20 M

Answer 1

Given:

Molarity of HCl = 0.65M

Volume of the given solution= 200ml

Final molarity needed= 0.20M

To find:

The volume of water needed for the dilution

Solution:

Dilution is a process in which water is added to the given solution to reduce the strength of the solution.

The opposite of dilution is concentration through which the strength of the given solution is increased.

Using the dilution formula,

M1 X V1 = M2 X V2

Here, M1 and V1 are the molarity and volume of the given solution

and M2 and V2 are the molarity and volume of the final solution

So, 0.65 X 200 = 0.20 V2

or V2= 65 X 2 / 0.20

        = 650ml

This is the final volume of the solution.

The volume of water required = Final volume - Initial Volume

= 650 - 200

= 450ml

Hence, 450ml of water must be added