Question

Given the partial equation ? NO3−+ ? S2− → ? NO+ ? S what must the coefficients be so that the electrons are balanced? Enter the equation coefficients in order separated by commas (e.g., 2,2,1,4, where 1 indicates the absence of a coefficient).

Answer 1

N in NO3- has oxidation state of +5

N in NO+ has oxidation state of +3

So, N in NO3- is reduced to NO+

S in S-2 has oxidation state of -2

S in S has oxidation state of 0

So, S in S-2 is oxidised to S

Reduction half cell:

NO3- + 2e- --> NO+

Oxidation half cell:

S-2 --> S + 2e-

Number of electrons is same in both half reactions.

So, balancing of electrons is not required. It's already balanced

Lets combine both the reactions.

NO3- + S-2 --> NO+ + S

Balance Oxygen by adding water

NO3- + S-2 --> NO+ + S + 2 H2O

Balance Hydrogen by adding H+

NO3- + S-2 + 4 H+ --> NO+ + S + 2 H2O

This is balanced chemical equation in acidic medium

Answer: This is balanced chemical equation in acidic medium