When `10 ml` of `0.1 M` acitec acid `(pk_(a)=5.0)` is titrated against `10 ml` of `0.1M` ammonia solution `(pk_(b)=5.0)`,the equivalence point occurs at `pH`

Options

A. `5.0`
B. `6.0`
C. `7.0`
D. `9.0`

Answer

C

Explanation

`CH_(3)COOH+NH_(3)rarrCH_(3)CO overset(-)(O)overset(+)(N)H_(4)(aq.)`
Ammonium acetate (salt of weak acid and weak base) does not undergo net hydrolysis `K_(a)=K_(b)`. Thus, its aqueous solution is neutral. The pH at the equivalence point will be
`pH=(1)/(2)[pK_(w)=pK_(a)+pK_(b)]`
`=(1)/(2)(14-5+5)=(14)/(2)=7`