The pOH of a solution is 10.75. What is the concentration of #OH^-# ions in the solution? Chemistry Acids and Bases pH calculations 1 Answer anor277 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# Answer link Related questions How do you determine ph of a solution? How do you determine pH at an equivalence point? How do you determine pH from molarity? What does alkalinity mean? What is a base? How do acid base indicators change color? What is a neutral pH? How does alkalinity affect pool water? Why is pH important in drinking water? How can I calculate the pH of a solution? See all questions in pH calculations Impact of this question 7100 views around the world You can reuse this answer Creative Commons License