The pH curve of the titration of weak acid with a strong base is given below:

Now choose the correct option among the following:

Options

A. pH at point `P = (1)/(3) pK _(a) - (1)/(2) log [A _(0)]` Where `A _(0)` is the initial concentration of weak acid
B. pH at point `Q = pK _(a) - (1)/(2) log "" (["weak acid"])/(["Salt"])`
C. pH at point `R = 1/2 pK _(w) + (1)/(2) pK _(a) + (1)/(2) log ` [salt]
D. pH at point `S = (1)/(2) pK _(w) + (1)/(2) log `[Base]

Answer

C

Explanation

At point .R. salt undergoes hydrolysis, `Delta T _(f) of NaCl = K _(f) (0.1), Na A to Na^(+) + A ^(-)`