Answer:
Concentration of hydroxide-ion at equivalence point =

Step-by-step explanation:

1 mol of
reacts with 1 mol of KOH to produce 1 mol of

At equivalence point, all
gets converted to
.
Moles of
produced at equivalence point is equal to moles of KOH added to reach equivalence point.
So, moles of
produced =

Total volume of solution at equivalence point = (25.00+43.76) mL = 68.76 mL
Concentration of
at equivalence point =

produced at equivalence point is due to hydrolysis of
. We have to construct an ICE table to calculate concentration of
at equivalence point.

I:0.0897 0 0
C: -x +x +x
E: 0.0897-x x x
![([HC_(3)H_(5)O_(2)][OH^(-)])/([C_(3)H_(5)O_(2)^(-)])=K_(b)(C_(3)H_(5)O_(2)^(-))=(10^(-14))/(K_(a)(HC_(3)H_(5)O_(2)))](https://img.qammunity.org/2020/formulas/chemistry/college/9xgi8ghkk7f5iis2k9t5155dicas44vyyd.png)
species inside third bracket represent equilibrium concentrations
So,

or,

So,
M =

So, concentration of hydroxide-ion at equivalence point = x M =
