Question

Enter your answer in the provided box. Determine the Kb of a weak base if a 0.30 M solution of the base has a pH of 11.98 at 25 ° C.

Answer 1

Let us consider that 'B'is a weak base which is mixed with H₂O. The reactionis, Blaw) + H₂O (1) Z BHT (aq) + OH (ar) Atinitial . c Atequi. (c-x) x x E so, dissociation constant Kb = [BH ] [OH-] [B] As, Bis a weak base, it reacts too less with H₂O. so acce :(-~) wc ...K6= 2 => x = 5KGXC or [own] = √koxc Taking logo) in both side, we get. .-logio Cow:] = -logo (ex Ku) "? .. or pot = -1² log ko - 1² loge o pon = pkb - 1 boge

Нота, рН = 11:48 bo" - 14 - р- - (14-11-a 9 ): 20 : 2:02 : 4 рь - 4 •я (os) е 2-o2 = , pь - (- о 26 ), р. , Р. - 2-o2. – -26 = 174 6. Арк. - р<ь - 2 52 e. - Dя Кь : 3:52 е Кь (-315 2) - 10 h, Kh. : 3 от 49 х10-4