The pOH of a solution is 10.75. What is the concentration of #OH^-# ions in the solution?

1 Answer
Feb 21, 2017

#[HO^-]=10^(-10.75)=1.78xx10^-11*mol*L^-1#

Explanation:

#pOH# is defined the same way as #pH#, except that here we address hydroxide ion concentration, i.e. #pOH=-log_10[HO^-]#......and thus #[HO^-]=10^(-pOH)=10^(-10.75)#.

Remember that since #pK_w=pH+pOH#

#-log_(10)10^-14=-log_(10)[H_3O^+]-log_10[HO^-]#

#-(-14)=pH+ pOH= 14#