The ionization constant of HA is 1.0 × 10−4 . What must be the ratio of [A−] to [HA] for the preparation of a buffer solution with a pH of 4.87?
In a buffer solution where HA is the weak acid/base.
Ionisation constant (Ka)=1.0*10^-4
We know PKa= -logKa
So, PKa= -log(1.0*10^-4)=4
According to Henderson equation we get-
Hence the ratio of [A−] to [HA] for the preparation of a buffer solution is 7.41