K_c is 1.67 × 10²⁰ at 25 °C for the formation of iron(III) oxalate complex ion:
Fe³⁺(aq) + 3C₂O₄^2-(aq) ⇌ [Fe(C₂O₄) ₃]^3-(aq)
If 0.0200 mol L^-1 Fe³⁺ is initially mixed with 1.00 mol L^-1 oxalate ion,what is the concentration of Fe³⁺ ion at equilibrium?

Question

Quizplus · Accepted Answer

Given the large excess of oxalate ion compared to Fe^3+, the reaction will proceed almost to completion, leaving a very small concentration of Fe^3+ unreacted. The correct answer, A) 1.44 × 10^-22 mol L^-1, reflects this scenario, indicating that nearly all Fe^3+ ions have reacted to form the complex ion.

Kc Is 1

K_c Is 1