Buffer facts

buffer solution

solution that contains equal amounts of weak acid and its conjugate base

buffers help

keep pH close to what you started with

acids have lower pH —>

reduce pH value

bases have higher pH —>

increase pH volume

neutral

Na, Cl

pH buffer =

pKa weak acid

buffer range =

pH range ± 1 pKa

Weak Acids usually have

an extra H

Acid Component of buffer reacts with added base

WA reacts with SB, SB is consumed, making

a little bit of conj WB, little pH change (bigger)

Base component of the buffer reacts with added acid

WB reacts with added SA, reuslts

w/ more WA, all SA is consumed, little pH change (smaller)

pH =

-log[H+]

Henderson equation for buffer

pH= pKa + log ([base]/[acid])

if you add volume, Molarity changes and you have to ICE in

moles

HCl is a

SA

OH is a

SB

if you add OH

the pH will increase

if you add H+

the pH will decrease

at equivalence point, pH always

=7

SA/SB have long

vertical titrations

Strong Acid ICE to

END

Weak Acid ICE to

Equilibrium

pH=pKa which means

½ equivalence point (midway point)

During the ½ equivalence point you have

equal amounts of WA and WB present