Question

Give that, $ E_{F{{e}^{2+}}/Fe}^{\circ }=-0.44V, $ $ E_{F{{e}^{2+}}/F{{e}^{3+}}}^{\circ }=-0.77V. $ if $ F{{e}^{2+}},F{{e}^{3+}} $ and Fe solid are kept together, then

• A. $ F{{e}^{3+}} $ decreases
• B. $ F{{e}^{3+}} $ increases
• C. $ F{{e}^{2+}} $ decreases
• D. $ F{{e}^{2+}},F{{e}^{3+}} $ remain unchanged

Answer 1

Answer: (A)

Cell reaction, $ 2F{{e}^{3+}}+Fe\to 3F{{e}^{2+}} $ $ E_{Cell}^{\circ }=0.77-(-0.44)=1.21\text{V} $ $ \Rightarrow $ $ F{{e}^{3+}} $ and Fe will reduce.