Question

An aqueous solution of hydrazine (\(N_2H_4\)) is electrochemically oxidized by \(O_2\), thereby releasing chemical energy in the form of electrical energy. One of the products generated from the electrochemical reaction is \(N_2(g)\). 

Choose the correct statement(s) about the above process

(A) \(OH^-\) ions react with \(N_2H_4\) at the anode to form \(N_2(g)\) and water, releasing 4 electrons to the anode.

(B) At the cathode, \(N_2H_4\) breaks to \(N_2(g)\) and nascent hydrogen released at the electrode reacts with oxygen to form water.

(C) At the cathode, molecular oxygen gets converted to \(OH^-\).

(D) Oxides of nitrogen are major by-products of the electrochemical process.

Answer 1

Correct options are (A) and (C)

\(\underset{\text{Oxidation}\\\text{ (Anode)}}{\overset{-2}N_2H_4} + \underset{\text{Reduction}\\\text{ (Cathode)}}{\overset 0 O_2} \longrightarrow\overset 0{N_2} + H_2O^{-2}\)

At anode:

\(N_2H_4 + 4OH^-\longrightarrow N_2 + 4H_2O + 4e^-\)

At cathode:

\(O_2 + 2H_2O + 4e^- \longrightarrow4OH^-\)

Complete reaction:

\(N_2 H_4 + O_2\longrightarrow N_2 + 2H_2O\) 

Statements (A) and (C) are correct.