Question

Which species is acting as a reducing agent in the following reaction?

$14H^{+} + Cr_{2}O_{7}^{2 -} + 3Ni \rightarrow 2Cr^{3 +} + 7H_{2}O + 3Ni^{2 +}$

• A. $Cr_{2}O_{7}^{2 -}$
• B. Ni
• C. $H^{+}$
• D. $H_{2}O$

Answer 1

Answer: (B)

Ni

Answer 2

: $14H^{+} + Cr_{2}O_{7}^{2 -} + 3Ni \rightarrow 2Cr^{3 +} + 7H_{2}O + 3Ni^{2 +}$

$Ni \rightarrow Ni^{2 +}$ (oxidation)

Hence, Ni acts as a reducing agent.