`100mL` of buffer of `1 M NH_(3)(aq)` and `1 M NH_(4)^(o+)(aq)` are placed in two compartments of a voltaic cell separately. A current of `1.5A` is passed through both cells for `20 m i n`. If only electrolysis of water takes place, then

Options

A. `L.H.S.` will increase
B. `R.H.S.` will increase
C. Both side will increase
D. Both side will decrease

Answer

B

Explanation

In `R.H.S.` formation of `OH^(-)` takes palce which reacts with buffer as
`NH_(4)^(+) + OH^(-) rarr NH_(3) + H_(2)O`
Thus `[NH_(4)^(+)]` decrease and `[NH_(3)]` increasee.
Also `pOH = pK_(b) + "log"([NH_(4)^(+)])/([NH_(3)])`
Thus, `pOH` decreases or `pH` increases. Similarly in `L.H.S.` formation of `H^(+)` shows.
`NH_(3) rarr H^(+) rarr NH_(4)^(+)` or `[NH_(4)^(+)]`
Increases and `[NH_(3)]` decreases. Thus `pOH` increases or `pH` decreases.