What is the hydroxide ion concentration of a lye solution that has a ph of 9.20?

To determine what the OH concentration is of a solution with a pH of 9.20. Simply remember that both the pH and POH add up to give a value equal to the ionization exponential value for water, which is 14.

Simply subtract 14 and 9.2 to find the pOH and then take the inverse log to find the OH concentration.

POH = 4.8

OH concentration = 1.58 X 10^-5 M.