Question

$ E{}^\circ $ for $ M{{g}^{2+}}\text{/}Mg=-\,2.37V, $ $ Z{{n}^{+2}}/Zn $ $ =-\,0.76\,V $ and $ F{{e}^{2+}}/Fe=-\,0.44\,V. $ Which statement is correct?

• A. Zn reduces $ F{{e}^{2+}} $
• B. Zn reduces $ M{{g}^{2+}} $
• C. Mg oxidises $ Fe $
• D. Zn oxidises $ Fe $

Answer 1

Answer: (A)

Higher the negative value of reduction potential, higher will be the reducing power. Hence, Mg reduces both $ Z{{n}^{2+}} $ and $ F{{e}^{2+}} $ . Zn can reduce $ F{{e}^{2+}} $ but not $ M{{g}^{2+}} $ . Similarly $ F{{e}^{2+}} $ can oxidise $ Zn $ and $ Mg $ both.