The `pK_(a)` of `CH_(3)COOH` and `pK_(a)` of `nH_(4)OH` is `4.76` and `4.75`, respectively. Calculate the hydrolysis constant of ammonium acetate `(CH_(3)COONH_(4))` at `298K` and also the drgree of hydrolysis and `pH` of its (a) `0.01M` and (b) `0.04M` solutions.

Answer

`K_h=3.25xx10^(-5), h=5.7xx10^(-3)` , pH = 7.005 same values for all concentrations.

Explanation

`pK_a=-log K_a=4.76 " " K_a=1.74xx10^(-5)`
`pK_b=-log K_b=4.75 " " K_b=1.77xx10^(-5)`
`K_h=(K_w)/(K_a. K_b)`
`=(1.0xx10^(-14))/(1.74xx10^(-5)xx1.77xx10^(-5))=3.25xx10^(-5)`
`h=sqrt(K_w/(K_a.K_b))`
`=sqrt(3.25xx10^(-5))=5.7xx10^(-3)`
`pH=1/2pK_w+ 1/2 pK_a -1/2 pK_b`
`=1/2xx14+1/2xx4.76-1/2xx4.75`
=7.005
The value is same for both concentrations .