I have a non-numeric problem relating the titration of CH
3COONa with HCl. The idea is to sketch the titration curve, which I'm guessing would start somewhere above 7 and then asimptotically approach the value of
[itex] -log[HCl] [/itex]. The more problematic thing is, I have to define an equation for [H
3O
+] in 4 points of interest:
-at the beginning of titration (I'm guessing before we add any HCl)
-before the equivalence point
-at the equivalence point
-after the equivalence point.
[H
3O
+] after the equivalence point would, in my opinion, equal the [HCl] and is defined as such:
[itex] \frac {c_{HCl}V_{HCl}}{V_{tot}} [/itex]
at the equivalence point, I figured:
CH
3COONa + HCl
CH
3COOH + NaCl
and as for [H
3O
+];
[H
3O
+] = [itex] \frac {K_a[CH_3COOH]}{[CH_3COO^-]} [/itex]
However I have no idea how to form the expression at the beginning and before the EQ. The pH has to, in my opinion, gradually decrease, so the concentrations of oxonium ions have to be lower, thus something additional must be in the denominator. I'm really lost here.