The concentration of hydroxide ion in household of ammonia that has a ph of 11.50 is calculated as follows
as we well know Ph +POh= 14
POh is therefore=14 -11.50= 2.5
POh is calculated as follows
POh= -log(-OH)= 2.5
-OH concentration is therefore = 10^-2.5 =3.162 x10^-3