g Chapter 18 Values The following values will be useful for problems in this chapter. Acid K Substance or Species K HF Ka = 7.2 ´ 10-4 NH3 Kb = 1.8 ´ 10-5 HNO2 Ka = 4.5 ´ 10-4 (CH3)3N Kb = 7.4 ´ 10-5 CH3COOH Ka = 1.8 ´ 10-5 [Co(OH2)6]2+ Ka = 5.0 ´ 10-10 HOCl Ka = 3.5 ´ 10-8 [Fe(OH2)6]2+ Ka = 3.0 ´ 10-10 HOBr Ka = 2.5 ´ 10 -9 [Fe(OH2)6]3+ Ka = 4.0 ´ 10-3 HOCN Ka = 3.5 ´ 10-4 [Be(OH2)4]2+ Ka = 1.0 ´ 10-5 HCN Ka = 4.0 ´ 10-10 [Cu(OH2)4]2+ Ka = 1.0 ´ 10-8 H2SO4 Ka1 = very large HBO2 Ka = 6.0 ´ 10-10 Ka2 = 1.2 ´ 10-2 (COOH)2 Ka1 = 5.9 ´ 10-2 H2CO3 Ka1 = 4.2 ´ 10-7 Ka2 = 6.4 ´ 10-5 Ka2 = 4.8 ´ 10-11 CH3NH2 K b = 5.0 ´ 10-4 ***************************************************************************** Calculate the pH of a solution in which [OH-] = 2.50 ´ 10-4M