Question

Out of the following, how many species than can act as both oxidising as well as reducing agent ?

$\begin{array}{cccc}1.& N{a}_2{O}_3& 2.& N_2{H}_4\\ 3.& FeS{O}_3& 4.& H_4{P}_2{O}_6\\ 5.& H_2{S}_2{O}_7& & \end{array}$

Answer 1

$\underset{–}{N}{a}_2{O}_3+3$
${\underset{–}{N}}_2{H}_4-2$
$Fe\underset{–}{S}{O}_3+4$
$H_4{\underset{–}{P}}_2{O}_6+4$
$H_2{\underset{–}{S}}_2{O}_7+6$

Species 1, 2, 3, 4 can behave as oxidant as well as reductant.