What is the hydroxide ion concentration in an aqueous solution with a pH of 4.33 at 25°C? Chemistry Acids and Bases pH calculations 1 Answer anor277 May 27, 2016 #pOH# #=# #9.67#, i.e. #[HO^-]# #=# #10^(-9.67)# Explanation: For water at #298*K#. #pK_w# #=# #14# And #pK_w# #=# #pOH# #+# #pH# #=# #14#, thus #pOH# #=# #9.67# #[HO^-]# #=# #10^(-9.67)*mol*L^-1#. 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 11523 views around the world You can reuse this answer Creative Commons License