What should be the pH of the aqueous layer to extract caffeine? There are three aqueous solutions that you may choose from.

Answer
A.
pH >14, using 2.5 M NaOH (aq)
B.
pH 1, using 0.1 M HCl (aq)
C.
pH 6.2, using 0.1 M NaHCO3 (aq)