12 Questions
What is the equilibrium constant defined as for the process of simple dissolution of a weakly acidic drug?
K = [HA(aq)] / [HA(s)]
What is the equilibrium constant defined as for the dissociation of a weakly acidic drug into ions?
Ka = [A-(aq)] / [HA(aq)]
How is the solubility (S) of a weakly acidic drug defined in terms of total concentration of solute?
S = K + KKa /[H+]
What type of plot gives a straight line with gradient KKa and intercept K?
Plot of S vs 1/[H+]
What is used to convert all the dissolved phenobarbitone to A-?
Excess base in the form of a pH 10 buffer solution
What equation is used to obtain the concentration of A- in solution?
A = Ɛcl
At what wavelength is the absorbance of the pH 10.0 solutions measured?
240 nm
What is encouraged to promote recrystallization of the phenobarbitone?
Scratching the side of the flask with a glass rod
What is used to dissolve most of the crystals in the process?
Heating on a hotplate with a buffer solution
What is used to transfer the solid phenobarbitone to a 100 mL conical flask?
Labelled sample vials
What should students do if there are spillages of phenobarbitone?
Notify staff
What should students do with the saturated solutions of phenobarbitone?
Filter off the crystals under gravity
Test your knowledge about the influence of pH on the solubility of drugs with this quiz. Explore the impact of pH variations on the aqueous solubility of weakly acidic drugs and the determination of equilibrium constants.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
