Given :
pH of solution of mixture of lactic acid and lactate is 4.26 .
To Find :
The ratio of the lactate concentration to the lactate .
Solution :
We know , pKa of lactic acid is :
pKa = 3.86 .
Now , the solution of lactic acid and lactate is a buffer solution .
So , pHof buffer acid is given by :
Putting all given values :
Taking anti log both the sides , we get :
Therefore , the ratio of the lactate concentration to the lactate is 2.51 .
Hence , this is the required solution .