Given a 0.200 M solution of anserine at its isoelectric point and ready access to 0.100 M HCl, 0.100 M NaOH and distilled water, describe the preparation of 1 L of 0.0400 M anserine buffered solution, pH 7.20.

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 = 0.04 M x 1000 ml

= 200 ml

So the 200 ml of 0.2 M anserine solution is required to prepare0.04 M of anserine.

0.1 M x = 0.04 x 1000 ml

= 400 ml

Therefore, 400 ml of HCl is needed.