Question

Cocaine is a weak organic base whose molecular formu- la is C17H27NO4. An aqueous solution of cocaine was found to have a pH of 8.53 and an osmotic pressure of 52.7 torr at 15 °C. Calculate pK, for cocaine. Hint: This problem is a bit more involved - you'll have to make use of material from previous chapters.

in decimal formation

Answer 1

Calculation for pKb is given in the attached file
Cocaine is a weak organic base whose moleculall formula is c17 H21 Noy. In aguous solution it is dissociated as the following process, Citta, No4 (ap) + H2O ce & Gif H21 NOCH + oH ado +20 e at equilibrium c (1-2) n ew cd c= cone, of base. - pH of the solution is 8.53. A s we know that pH t P OH = 14 in pott = 14-8.53 = 5.47 By using the formula po gurem osmotic for weak base, pohad Pkb - I loge. press mee = 52.7 toms, = 0.0693 adm- ił = CRT 8.0693 atm @X01082 let admmole - 0.0693 [ Tempa 150] 13 & 2.93 x 100 males 0.082 X 288 Р. Т. о

in poH = + Pkb- & loge i 5.47= bpkb - log (2.93 X20-3) & Pkb = 8.40 ] son Pkb ford cocaine solution is & 8.407