A buffer is simply a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid. Buffers work by reacting with any added acid or base to control the pH. ... The strong acid's proton is replaced by ammonium ion, a weak acid. The strong base OH- was replaced by the weak base ammonia.
Do buffers always contain a weak acid?
A buffer solution usually contains a weak acid and its conjugate base. When H+ is added to a buffer, the weak acid's conjugate base will accept a proton (H+), thereby “absorbing” the H+ before the pH of the solution lowers significantly.
How do buffers react with strong acids?
If a strong acid is added to a buffer, the weak base will react with the H+ from the strong acid to form the weak acid HA: H+ + A- → HA. The H+ gets absorbed by the A- instead of reacting with water to form H3O+ (H+), so the pH changes only slightly.
