Question

The answer to part b is pH= 10.70, %ionization= 2.0%.

UN (aq) + H2O(1) = NO (aq) + OH(aq) Kb = 1.0 x 10-5 @ 25 °C H Benadryl BH a. How would the following actions disturb the equilibrium? Which direction will the system go to reestablish equilibrium? How would the following be affected by the indicated actions (increase or decrease)? ACTION AG Direction of system (Benadryl] [BH"] [OH-] | [H*] pH Dissolving more Benadryl Dissolving more ammonium chloride salt of Benadryl, BHCI (structure given below): Adding NaOH(aq) Adding HCl(aq) b. Calculate the pH and % ionization of a 0.025 M Benadryl solution at 25°C. c. What is the pH of a Benadryl solution that is comprised of 0.025 M Benadryl and 0.015 M ammonium chloride salt of Benadryl at 25 °C? Compared to part b, how does adding BH(aq) affect the pH of the solution?

The answer to part c is pH=9.22

Please show all work

Answer 1

LON- (ar) + 1,0 () = Danke # (Bit) ton Kb=100x105 The reaction is in equilibrium. According to Le chatelier principle when any system at equilibrium for a long period of time is Subjected to change in concentration, temperature Volume or pressure the system changes to a new equilibrium and this ca Counteraets the applied Change. . At equilibrium AGBT-0 R = Equé librium constant We know the reaction isotherm, AG = RT lnl. Q = Renetion Quotient k = Equilibrium ca When a K + 46 0 e eouol buu, If Q>k then 4G = tve, so the reaction occurs in backward (left) direction ice towards reactant. If Q <k then equilibrium shifted towards right he towards Prednets.

Action AG lo recent Benachrig (BHB COH) CHA | PH ] -ward) Dissolving and negative Toward Increases Increases Increases decreased Increases more going Right Benadrul I-ve (Forward Dissoning mored Pasitive Tourends Increases Inercases deeplasses Increases Deezeases BHce tve back Adding Positive Toward Increas & Decreases Increases / decreases decreases Nach Adding negative towards Decreases increases Increases the Increases Hel left the -ve Right decreases pot expression Benadryl ich wear base, so it's is as follows - POH - I pkb - I loge 6 e=concentration of base = 0.025M 8. Don = - 12 legko - loge (k. Dissociation pot = -1 lag (155) - log (0.025) Constant of base 80. POH = 25+ 0.801 a pOH = 3,301 We know pH +POH = 14 that Se PH - 14-POH = 14-3.301 - 10.699 Hence pH = 10.699 ~ 1007 pH = 10.7

If x is degree of dissociation then 8 + H2O = 8H + OH (1-age ac xe at eam. Kb = [BH], [or ] x c.ac (1-2).C Since, & LL1 So, 1-x ř a ng ned heres, Kb=de or a = √ Ko V 0.025 = 2x102 Gr. x = 0.02 Gr. x = 2%. So, degree of dissociation = 2%)

O Mixture of Benadryl and ammonium Chloride Salt copie de buffer solution- hasselbalch equation From Henderson We can write- pon = pkb + dog [sact] гра8) (concentration of Nigel = [sal) = 0,015m 2 concentration of Benadryl = [Base = 0.025m TK6=105 08, PK6 =- logK6= -log(155) 55 So, LOH = 5+ leg (0.05 ) or poh = (5 - 0.2218) = 4.7782 OH PH + por = 14 so, pH = 14-poH = (14- 4.7782) of pH = 9.2218 ~ 9. 22 So, (pH = 9.22 the pH due to common Adding BHt decreases iou (BHt) effect.