Salts' Function In Buffers

[704578485]

Yesterday in lecture professor Lavelle emphasized the importance of salt in a buffer. I grasped what he was saying about that if your buffer is a weak acid and it's conjugate base, the addition of a salt will allow the base concentration to rise and a 1:1 weak acid to conjugate base concentration will be achieved. This provides you with an optimum buffer. The thing I do not get is why does the addition of a salt increase the conjugate base concentration?

[Chem_Mod]

The salt is the provider of the conjugate base, therefore by adding the salt will increase the conjugate base concentration. We add salts because they do not change the volume of the solution and because the cation that is paired with the conjugate base does not affect the pH (usually Na⁺ or K⁺)

[JasmineChavez 1E]

The salt is the provider of the conjugate base, therefore by adding the salt will increase the conjugate base concentration. We add salts because they do not change the volume of the solution and because the cation that is paired with the conjugate base does not affect the pH (usually Na⁺ or K⁺)

How does the salt increase the conjugate base but not affect pH? i though pH was the concentration??

[Yvonne Tran 2F]

The pH has to do with the concentration of H+, not the concentration of the conjugate base. pH=-log[H+]