a) What is fellesioneffekten?

Question

 
Veronal is a barbiturate (structure see above). Barbiturates is a substance class which occur in a variety of drug classes, including sleep medications (hypnotikasedativa), in painkillers (anesthetics) and anticonvulsants. A barbiturate is a weak acid. Veronal is usually given in the form of its sodium salt.
 
b) Determine the pH of a 250 mL solution containing 10 mg of sodium salt of veronal with molecular formula NaC8H11N2O3? For Veronal is Ka = 3.7 x 10-8.
 
c) As a pharmacist wants you to solve the sodium salt of veronal in a buffer, and you can choose between these two possibilities: i) 0.5M KH2PO4 / K2HPO4 or ii) 0.5 M NaH2PO4 / Na2HPO4. Discuss solubility of sodium salt of veronal in the two buffer