Question

what two ingredients are used to prepare basic buffer solution??

Answer 1

Alkaline buffer solutions

An alkaline buffer solution has a pH greater than 7. Alkaline buffer solutions are commonly made from a weak base and one of its salts.

A frequently used example is a mixture of ammonia solution and ammonium chloride solution. If these were mixed in equal molar proportions, the solution would have a pH of 9.25. Again, it doesn't matter what concentrations you choose as long as they are the same.

Answer 2

Right on the money, BP... If I may add, how about an acidic 50/50 buffer. HOAc/NaOAc (Acetic Acid/Sodium Acetate), Ka=1.8x10^-5... For any 50/50 acidic buffer given the Ka of the weak acid, the buffer pH = pKa = -log(Ka) = -log(1.8x10^-5) = -(-4.74) = 4.74. For any 50/50 alkaline buffer pH = 14 + pKb of weak base. pKb = -log(Kb) For a 50/50 Ammonia/Ammonium Chloride buffer given pKb(NH4OH) = 1.8 x 10^-5 => pH = 14 + (-log(Kb)) = 14 + (-log(1.8x10^-5)) = 14 + (-4.74) = 14 - 4.74 = 9.25... Good job, BP.