The Student Room Group

why does altering the ratio of weak acid : it's salt alter pH of the buffer solution?

So a weak acid and it's salt is used to make a buffer. If the ratio of them is changed the pH changes. My reasoning is that the amount of acid dissociation would be altered now. Am I right?
Reply 1
In a buffer the ratio is determined by Ka. Adding/removing H+ makes the ratio of [H+][A-]/[HA] no longer equal to Ka, so the equilibrium shifts until the ratio once again equals Ka.

Which is a fancy way of saying, you are correct.

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