In the ring test of `NO_(3)^(-)` ion, `Fe^(2+)` ion reduces nitrate ion to nitric oxide, which combines with `Fe^(2+)` (aq) ion to form brown complex .
Write the reactions involved in the formation of brown ring.

Explanation

`{:(underset("Nitrate ion")(NO_(3)^(-)(aq))+3Fe^(2+)+4H^(+)(aq) rarr underset("Nitric oxide")(NO(g))+3Fe^(3+)(aq)+3H_(2)O(l)),(" "[Fe(H_(2)O)_(6)]^(2+) + NO(g) rarr underset("(Brown complex)")underset("Pentaaquanitrosonium iron (I)")([Fe(H_(2)O)_(5)NO]^(2+))+H_(2)O):}`