Question

can someone please explain how exactly does the buffer solution of ammonia and ammonium chloride work?

Answer 1

a solution that consists of a weak base, in this case, ammonium chloride. it's used to prevent drastic change in pH of a solution. Often used to keep a pH constant in a system. This is useful when workng with enzymes since enzymes often require specific pH environmets, often body pH environments, which is usually around pH of about 6.8-7.5.

Answer 2

A mixture of an acid (ammonium ion) and its conjugate base (ammonia) will remain within 1 unit of pH below or above the pKa of the acid-base couple, as long as the two substances remain within a ratio of 1:10 to 10:1.

If there is a large amount of those substances in you solution, you would have to add a LOT of an acid or of a base to go beyond the 1:10 - 10:1 ratio.

Inversely, any moderate amount of added acid or base will only lead to a very small change in pH.