2- calculate the percentage of the following compounds that would be extracted under the condition specified:
a- A solution containing a basic drug, pka=9.2 in and oral liquid is mixed with a buffer having a PH of 7.2 and is extracted with an equal volume of chloroform(the partition coefficient of the unionized base into chloroform is 500)
b- An acidic drug with a pka of 4.2 is extracted from a solution of ph 4.50 with an equal volume of chloroform( the partition coefficient of the unionized acid is into chloroform is 300)
3- Extracts containing benzylpenicillin were prepared for analyses on buffer ph6.5 at 25C the rate constant for the hydrolysis of benzylpenicillin under these conditions is 1.7 multiplied by 10-7 what is the maximum length of time the solution can be stored before analysis so that no more than 1% decomposition occur?