The graph below, which is related to a titration curve, shows the fraction () of the stoichiometric

The graph below, which is related to a titration curve, shows the fraction (ƒ) of the stoichiometric amount of acetic acid present as non-ionized CH₃COOH and as acetate ion, CH₃COO^-, as a function of the pH of the solution containing these species.

(a) Explain the significance of the point at which the two curves cross. What are the fractions and the pH at that point?

(b) Sketch a comparable set of curves for carbonic acid, H₂CO₃. How many carbonate-containing species should appear in the graph? How many points of intersection should there be? at what pH values?

(c) Sketch a comparable set of curves for phosphoric acid, H₃PO₄. How many phosphate-containing species should appear in the graph? How many points of intersection should there be? at what pH values?

Transcribed Image Text:

Fractional part of total, f 1.0 - 0.9 - 0.8- 0.7- 0.6 - 0.5 0.4 0.3- 0.2 - 0.1 CH₂COOH 1 1 1 | 2 3 4 5 CH₂COO™ 1 1 I 6 7 8 9 10 11 12 pH