What is hydroxide ion concentration, [oh-], in a 1.37 x 10^-5 m solution of barium hydroxide (ba(oh)2)?

The  concentration   of  hydroxide ion  (-OH)  in  1.37 x10^-5 m solution  of Ba(OH)2  is  calculated  as   follows

write   the  equation  for  dissociation  of Ba(OH)2

Ba(OH)2 =  Ba^2+(aq)   + 2OH^-(aq)

by use  of  mole  ratio between Ba(OH)2 to OH^-  which   is  1:2  the   concentration  of OH^-  =  2x  ( 1.37 x10^-5) = 2.74  x10^-5 M

The answer would be

Iwould you figure it out but you don't have a picture or in your question as to what the physical property you're looking for is