Question

$K_{2}C{r}_2{O}_7$ react with hydrazine to form product. The oxidation state of $Cr$ in the product will be:

• A. $+4$
• B. $+3$
• C. $+5$
• D. $+2$

Answer 1

The correct option is B $+3$

$\stackrel{+6}{K_{2}C{r}_2{O}_7}+N_2{H}_4+H_{2}S{O}_4$

$\downarrow$

$\stackrel{+3}{C{r}_2(S{O}_4{)}_3}+N_2+K_{2}S{O}_4+H_{2}O$

Oxidation state $Cr$ in product is $+3$.