To pH value of decinormal solution of `NH_(4)OH` which is 20% ionised is

Options

A. 12.95
B. 12.3
C. 14.7
D. 13.3

Answer

B

Explanation

Concentration of `NH_(4)OH` solution =0.1 N
Concentration of `OH^(-)` ions in solution,
`[OH^(-)]=20% " of " 0.1 N =(20)/(100)xx0.1
=0.02 N
`implies pOH =-log[OH^(-)]=-log (0.02)
`=2-0.301`
`implies pH=14-pOH=12.30`