How to make acidified water pH2 with HCl

You need the concentration of H+, equal to the concentration of HCl, to be .01 M. That's .3646 g HCl per 1 L of water. How you get there depends upon the concentration of the HCl solution with which you are starting and the volume of the final solution at pH = 2. You will need to use M1V1 = M2V2.

Hope this helps.