For the following reaction As2O3 + NO to the exponent 3- ____H3AsO4 +NO?

Question

a.Balance using either method you learnt (oxidation numbers or ion-electron method)
b. Indicate oxidizing agent
c. Indicate reducing agent

Answer 1

The As atoms are oxidised from +3 to +5, and the N atoms (I think you started with nitrate ion) are reduced from +5 to +2. So a 2:3 ratio is needed between them.
The nitrate ions are the oxidising agent.
Then look at how many surplus O atoms there are on one side of the equation, and balance them on the other side with H2O.
Then do the same with H atoms, and balance them with H+ ions.