Question

1) Calculate the pH for the titration of 60.00 mL of a 0.1500 M methylamine with 45.00 mL of 0.1000 M HCl. Kb = 4.42 × 10−4

2) One liter of a pH 5.00 propionic acid buffer with a total concentration of 60 mM must be prepared. Calculate the mmols propionic acid and sodium propionate needed to prepare the buffer. Ka = 1.34 x 10-5 for propionic acid

please show your work and clear net answer

Answer 1

metyl amine CH3-NH CH3-NH2HC CH-M3Ci | mde of CH-NH2 Teacea Cuith Ko=4.42x14 metylamine ix a CACOK baje . 3 i Conjugak acid of meteylamime A The Mixtua af A amd formed m the doluhon make the oluhon aa buffen Amount of methylamine (eft in the soluhon nifial amouwl of A) Amount of Hcl 4S mtx »IM 11 4S mL x o.1 MmoL mL 7 mL mmoL 4.5 mmoL 4.S mmoL 17

Tofal volume 60 mt 45 mi l0S ml Amont of foxmed A mount of HA oMumed 1 17 mL 4.S mmoL Concemtakon of (A) left insoluhon 4SmmoL 0.0428 M COncentahion of B 4 S mmoL 11 a.0428 M 17 toS mL HemderRon Hauelloalch iA uud fr th buffen dolukon po 0428 094.42x104 6-0428

рон 3.354S7 PH pot 14 eH 14- 3-354S7 to. 64S 2) Hendenon tawalbalch euakon foy ueak aad (Salf of Cotak acdmiu iA uud Sale7 log PH- pa Cven that Pvofionic audl Csadium Propionak Sale -lo1-34xio Sale] S 4.8728 salt Salt Acid O.1272 tog O-1272

Sale -3403 Satt) = 3403 (AcidJ ACid Salt = 60 mm Acrd 3403 tacid 6s mM Aad 2S.637Mm 2-3403 Salt) 3463 x 25.631 mm = 34.36 mm IL solukan Aid equived = 25-637 Mm mol. To make = 2S.631 mmol = 2S.64 mmol Simi lanty Salt requived - 34.36 mmol