Post on 01-Jan-2016
description
Theory of Indicators
HInd (aq) H⇌ + (aq) + Ind- (aq)
Colour 1 Colour 2
Kind = [H+][Ind-]/[HInd]
log10 Kind = log10 [H+] + log10 ([Ind-]/[HInd])
-log10 Kind = -log10 [H+] + -log10 ([Ind-]/[HInd])
pKInd = pH – log10 ([Ind-]/[HInd])
log10 ([Ind-]/[HInd]) = pH- pKInd
Theory of Buffers
HA (aq) H⇌ + (aq) + A- (aq)
KA = [H+][A-]/[HA]
log10 KA = log10 [H+] + log10 ([A-]/[HA])
-log10 KA = -log10 [H+] + -log10 ([A-]/[HA])
pKA = pH – log10 ([A-]/[HA])
pH = pKA- log10 ([HA]/[A-])