Question

To have solutions of HCl and acetic acid (CH₃CO₂H) with the same pH, which of the following needs to be done?

The concentration of each solution needs to be the same.

The concentration of HCl needs to be higher.

The concentration of acetic acid needs to be higher.

The solutions can never have the same pH.

Volume of acetic acid solution must be lower.

Answer 1

HCl is a strong acid which dissociates completely in aqueous solution and acetic acid is a weak base which do not dissociates completely. However the similarity is that the both liberates H+ ions which is measured in terms of pH.

Now, if we have to make solution of HCl and acetic acid with same pH, it is possible only when concentration of acetic acid should be higher and HCl should be lower.

Suppose pH of 0.1M acetic acid is 2.88.

so in order to make HCl solution with pH 2.88 concentration required is only 0.0013M.

So, option(C) is correct