Question

This is a fractional composition diagram for fumaric acid. Can someone please show what a fractional composition diagram for a diprotic acid would look like? Thanks

H COH Fractional composition HOCH pk, = 3.02 pk = 4.48 0 1 1 2 3 4 5 6 7 PH FIGURE 10-4 Fractional composition diagram for fumaric acid (trans-butenedioic acid). At low pH, HA is dominant. At intermediate pH, HA is dominant; at high pH, A2- dominates. Because pk, and pKy are not separated very much, the fraction of HA never gets very close to unity.

Answer 1

which Let the diforotic acid is HaA dissociates as pkar H L & Acid] For on Henderson At anolbouch equation we get & rochere rcB7 pH = pka & log - CAI (B- conjugate barevan Here, HA is conjugate base (CB) J. of word that A.2 is conjugate bare (CB) of weak and HAT when, fraction of weak acid in 0.5 & probiour of conjugate bare nos then, papka + log (os) = pka to in pHepka .: when proction compositionin 0.5 then corresponding pt in Pka. For di frotic aid (that) when LA XHA & O.S then. pta pka, Similarly when, LHA = LA- = 0.5 then, pha pkan [where, &a fraction]

2. Fractional composition. O.S . LAA--LA2- ka bilan PH Fractions composition diagram of di protic reid (H2A)