When 0.05 M dimethyl amine is dissolve in 0.1 M NaOH solution then the percentage dissociation of dimethyl amine is : `(K_(b))_((CH_(3))_(2)NH)=5xx10^(-4)`

Options

A. `5xx10^(-5)`
B. `5xx10^(-3)`
C. `5xx10^(-1)`
D. `5xx10^(-2)`

Answer

C

Explanation

`"0.05 M dimethyl amine (weak base), "K_(b)=5xx10^(-4)`
`"0.1 M NaOH"`
`(OH^(-))=0.1+0.05 alpha ~~ 0.1`
`K_(b)=([Calpha][OH^(-)])/([C-Calpha])" "5xx10^(-4)=(alphaxx0.1)/(1-alpha)" "alpha=5xx10^(-1)%`