Now, find the concentration of H+ ions to OH– ions listed in Table B of your Student Guide for a solution at a pH = 11. Then divide the H+ concentration by the OH– concentration. Record these concentrations and ratio in Table C. What is the concentration of H+ ions at a pH = 11? mol/L What is the concentration of OH– ions at a pH = 11? mol/L What is the ratio of H+ ions to OH– ions at a pH = 11? :1, OR 1: