In the two half-reactions shown below,which chromium species is the strongest oxidizing agent? Cr₂O₇^2-(aq) + 14 H⁺(aq) + 6 e^- → 2 Cr³⁺(aq) + 7 H₂O(l) E° = + 1.33 V
CrO₄^2-(aq) + 4 H₂O(l) + 6 e^- → Cr(OH) ₃(s) + 5 OH^-(aq) E° = - 0.13 V

Question

Quizplus · Accepted Answer

The half-reaction with the higher E° value (more positive) is the stronger oxidizing agent. In this case, half-reaction A has an E° of +1.33V, while B, C, and D have E° values of +0.50V, -0.13V, and -0.40V respectively. Therefore, chromium in the Cr₂O₇^2- half-reaction is the strongest oxidizing agent.

In the Two Half-Reactions Shown Below,which Chromium Species Is the Strongest