How is the pH of a solution related to the #[H_3O^+]#? Chemistry Acids and Bases pH calculations 1 Answer anor277 Jun 23, 2016 #pH=-log_10[H_3O^+]# Explanation: So given a neutral solution, #[H_3O^+][HO^-]=10^(-14)#, and since, by definition, #[H_3O^+]=[""^(-)OH]#, i,e,. #[H_3O^+]# #=# #10^-7*mol*L^-1# And thus #pH# #=# #-log_10(10^-7)# #=# #7# (because #log_(a)a^b# #=# #b# by definition). You might need to review the logarithmic function. 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 2916 views around the world You can reuse this answer Creative Commons License