Question 2.3 The pH of a hydrochloric acid solution at 25°C is 311 The concentration of the hydroxide ions in this solution is A. [OH-] = 2 8 x 10-11 mol.dm-3 B [OII] = 3 5 x 104 mol dm3 C [OH-] = 10 x 10-7 mol dm-3 D [OH-] = 2 8 x 103 mol dm-3 E None of the above.