A solution of ammonia has a pH of 11 point 8 What is the concentration of OH raised to the negative power ions in the solution? Useful formulas include open bracket cap h sub 3 cap o raised to the plus power close bracket is equal to 10 raised to the negative pH power , open bracket OH raised to the negative power close bracket is equal to 10 raised to the negative pOH power , pH plus pOH is equal to 14 and open bracket cap h sub 3 cap o raised to the plus power close bracket times open bracket OH raised to the negative power close bracket is equal to 10 to the negative 14 power