Final answer:
In the reaction AsO3- + 2NO2 → AsO2 + 2NO3- +3H2O + 8e-, AsO3- acts as the reducing agent and NO2 acts as the oxidizing agent. The reaction is balanced by following a series of steps.
Step-by-step explanation:
The process to balance this reaction and identify the oxidizing and reducing agents involves some steps. First, balance the atoms other than hydrogen and oxygen in the reaction equation. This gives you AsO3- + 2NO2 → AsO2 + 2NO3-. Then balance the oxygen atoms by adding water molecules, resulting in AsO3- + 2NO2 → AsO2 + 2NO3- + H2O. Next, balance the hydrogen atoms by adding 4OH- ions on both sides giving 2OH- + AsO3- + 2NO2 → AsO2 + 2NO3- +3H2O. Now balance charge by adding electrons: 2OH- + AsO3- + 2NO2 → AsO2 + 2NO3- +3H2O + 8e-. Finally, you complete the half-equations and add them together. In this redox reaction, AsO3- is the reducing agent and NO2 is the oxidizing agent.
Learn more about Redox Reactions