Question

The correct order of chemical reactivity with water according to electrochemical series.

• A. $O_{2}$
• B. $MnO_{4}^{-} + 8H^{+} + 5e^{-} \rightarrow Mn^{2 +} + 4H_{2}O;Eº = 1.51V$
• C. $Cr_{2}O_{7}^{2 -} + 14H^{+} + 6e^{-} \rightarrow 2Cr^{3 +} + 7H_{2}O;Eº = 1.33V$
• D. $Fe^{3 +} + e^{-} \rightarrow Fe^{2 +};Eº = 0.77V$

Answer 1

Answer: (A)

$O_{2}$

Answer 2

The standard reduction potential of $K^{+}$,

$Mg^{2 +},Zn^{+ 2}Cu^{2 +}$ increase in this order.