The dissociation of weak electrolyte (a weak base or weak acid) id expressed in terms of Ostwald dilution law. An acid is a substance which furnishes a proton or accepts an electron pair whereas a base is proton acceptor or electron pair donor. Storonger is the acid weaker is its conjugate base. The dissociation constants of an acid `(K_(a))` and its conjugate base are related by `(K_(w)=K_(a)xxK_(b)`, where `K_(w)` is ionic prodcut of water equal to 10-14 at `25^(@)`C. The numerical value of `K_(w)` however increases with temperature. In a solution of an acid or base `[H^(+)][OH^(-)]=10^(14)`.Thus, the `[H^(+)]` in a solution is expressed as : `[H^(+)]=10^(-pH)`and `pH+pOH=14`. Buffer solutions are the solutions which do not show appreciable change in the pH on addition of small amount of acid or base.
Which of the follwoing statement are true?
(P) `CIO_(4)^(-)` is weaker base than `CIO_(3)^(-)`
(Q) The degree of dissociation of water at `25^(@)C` is `1.8xx10^(-9)`
(R)The equilibrium constant for dissociation of `H_(2)O` is `1.8xx10^(-16)`
(S) `PO_(4)^(3-)` is conjugate acid of `HPO_(4)^(2-)`

Options

A. P,Q,R
B. Q,R,S
C. P,Q,S
D. P,Q

Answer

a