Question

QUESTION 13 Which of the following is false? a. The conjugate base of a relatively weak acid is relatively strong b. Buffer solutions resist changes in pH c. at 25 pH + pOH = 14 d. To make an effective buffer, the pka of the weak acid should be as far away as possible from the pH that you wish to maintain. e. When titrating a weak monoprotic acid with NaOH, at the Veq pt/2, the equation pH pka is valid.

Answer 1

, на 2 н +А” base acid Answer d) a) By Bronsted lowry definition of acids and bases : . Acids are lit donors. Bases are itt acceptors - HA 2 H+ +A Weal aid strong String : Weak conjugate O confugare base so a) is true b) Buffers are the solutions | mixtures that resist change in pH. S so b) iu true c) at 25°c ph & por=14 true as pH = -log Ent], pon = -log [on] ... at 25°c kw= lut] lon-] = 10:14. log (Cu +) [on-]) = 107(10):19 (log(xy) = loge +logy) loglut]+ tog [on-] = -14 log (10) I log10r = alog 10 . log Cut] + log Con-1=-14 -log ent] - log (on-]=14 ph+ pon =14 - 80 c) is tru d) false - as to make effective buffer pH = pka Il S that is pka should not be too far from ph required. e) at Veg/2, pu=pka for titration of weak monoprotic acid. at reqla, salt 1 = (weak acid ] - Cucid? pu= pka so e) is true Answer d) is false + log balt) = pkat pu= pkat log healt]