text: Actually, yes.\n\npH is the negative of the logarithm of the concentration of hydronium ion in aqueous solution:\n\npH = -log[H3O+]\n\nSo, for example, if one had a theoretical concentration of hydronium ion of 10, then pH would be -1.  And since \n\nKw = 10^-14 = [H3O+]*[OH-]\n\nthe resulting [OH-] would be 10^-15.\n\nthe resulting pH value would be -1, and the pOH 15, which would fit the equation pH + pOH = 14.