Question

Write a chemical equation for the reaction of the weak acid and water. If the titration hadd mmore than one equivalence point, there willl be more than one Ka and also more than one chemical reaction because it is a polyprotic acid.

a)ascorbic acid

b)potassium bisulfate

c)KHP

d)phosphoric acid (polyprotic)

Name	pKa	Ka
Ascorbic acid	0.12	0.76
Potassium bisulfate	0.08	0.83
KHP	0.08	0.83
Phosphoric Acid	0.05,0.42	0.89,0.42

Answer 1

Solution :-

Following are the equations of the weak acid and water.

Ascorbic acid (C6H8O6)

C6H8O6 + H2O ---- > C6H7O6^- + H3O^+

Reaction for the potassium bisulfate (KHSO4)

KHSO4 gives the HSO4^- ion which acts as weak acid

HSO4^- + H2O ---- > SO4^2- + H3O^+

Reaction for the KHP(C8H5O4K)

KHP gives C8H5O4^- ion which acts as weak acid

C8H5O4^-   + H2O ----- > C8H4O4^^2- + H3O^+

Phosphoric acid H3PO4

Its triprotic acid so it can have 3 equations as follows

H3PO4 + H2O ---- > H2PO4^- + H3O^+

H2PO4^- + H2O ---- > HPO4^2- + H3O^+

HPO4^2- + H2O --- > PO4^3- + H3O^+