topic 6: buffers & titration

what are buffers?

solutions that resist a change in pH upon addition of small amounts of acid or base

what does a buffer contain?

a weak acid and its conjugate base or a weak base and its conjugate acid

how do buffers work when acid id added (H+)?

the added H+ is neutralized by conjugate base to form acid

the concentration of H+ in the solution does not change

pH does not change

how do buffers work when base is added (OH-)?

the added OH- is neutralized to form water and conjugate base

the concentration of the OH- in the solution does not change

pOH and pH does not change

a buffer functions based on? (weak base/conjugate base)

presence of weak base/conjugate base to neutralize added acid

a buffer functions based on? (weak acid/conjugate acid)

presence of weak acid/conjugate acid to neutralize added base

what is buffering capacity?

ability of a buffer to tolerate added acid or base without changing its pH

when is a buffer more useful?

a buffer is more useful when it has equal amounts of acid and base

what are acid-base titrations?

titrations are used to determine the total concentration of acid or base in a solution

what is the equivalence point?

point at which stoichiometrically equivalent quantities of acid and base have reacted

what is the equivalence point of strong acid & base

7

what is the equivalence point of weak acid & strong base?

>7

what is the equivalence point of strong acid & weak base?

<7

what is the equivalence point of weak acid & base?

unknown