Question

NO3 + 4H → NO + 2H2O
How many electrons required balancing the equation?
A.
3e gain
B. 3 e loss
C. 2 e
D. None of these

Answer 1

Explanation:

B is the correct option

Answer 2

The unbalanced redox equation is as follows:

NO3−+4H++e−→2H2O+NO

The oxidation numbers for nitrogen has been assigned. 

+5NO3−+4H++e→2H2O++2NO

This is a reduction half equation. All atoms are balanced.

We balance charges by adding the appropriate number of electrons.

NO3−+4H++3e−→2H2O+NO

This is a balanced reduction half-reaction.

Thus, the number of electrons required to balance the equation is 3.

Hence, the correct option is C