Solution :
Given :
Amount of anserine solution = 0.200 M
pH value is = 7.20
Preparation of 0.04 M solution of anserine from the 0.2 M solution.
0.2 M x [tex]x[/tex] = 0.04 M x 1000 ml
[tex]x[/tex] = 200 ml
So the 200 ml of 0.2 M anserine solution is required to prepare0.04 M of anserine.
0.1 M x [tex]x[/tex] = 0.04 x 1000 ml
[tex]x[/tex] = 400 ml
Therefore, 400 ml of HCl is needed.