Question

What is the ratio of the concentration of sodium acetate to the concentration of acetic acid at ph 5.75?

Answer 1

To get the ratio of the concentration of sodium acetate to the concentration of acetic acid we are going to use H-H equation:

when:

PH = Pka + ㏒[salt/acid]

when the Ka of acetic acid = 1.75 x 10^-5 

so, we can get Pka from this formula:

Pka = -㏒Ka

       = -㏒1.75 x 10^-5

      = 4.76

and when we have PH = 5.75, so by substitution:

∴ 5.75 = 4.76 + ㏒[acetate/ acetic acid]

∴ [acetate/acetic acid] = 9.77

∴ the ratio of a concentration of acetate to acetic acid 9.77