Question

Which substance serves as a reducing agent in the following reaction?
$14H^{+}+C{r}_2{O}_7^{2-}+3Ni\to 2C{r}^{3+}+7H_{2}O+3N{i}^{2+}$

• A. $H_{2}O$
• B. $Ni$
• C. $H^{+}$
• D. $C{r}_2{O}_7^{2-}$

Answer 1

Answer: (B)

$Ni$

The redox reaction is given below:
$14H^{+}+C{r}_2{O}_7^{2-}+3Ni\to 2C{r}^{3+}+7H_{2}O+3N{i}^{2+}$
+6 0 +3 +2
As $Ni$ is oxidised, it will act as reducing agent.