Question

If a buffer solution is 0.190 M in a weak acid ( a=3.6×10−5) and 0.480 M in its conjugate base, what is the pH?

Answer 1

`pk_b = -log ( K_b)\\\\pk_b = - log ( 3.6 * 10^(-5))\\\\pk_b = 4.44`

We know, pH of this solution :

`pH = pK_a + log ( (|conjugate\ base|)/(|weak \ acid|)\\\\pH = 4.44 + log((0.480)/(0.190))\\\\pH = 4.44 + 0.40\\\\pH =4.84`

Hence, this is the required solution.