Question

3. Подберите коэффициенты методом электронного баланса, укажите окислитель и восстановитель: V+ HNO3 = V2O5 + NO2+H2O

Answer 1

Balancing the Equation using the Electron Balance Method

To balance the given equation using the electron balance method, we need to ensure that the number of electrons lost in the oxidation half-reaction is equal to the number of electrons gained in the reduction half-reaction.

The given equation is:

V + HNO3 = V2O5 + NO2 + H2O

Let's break down the equation into the oxidation and reduction half-reactions:

Oxidation Half-Reaction: V → V2O5

Reduction Half-Reaction: HNO3 → NO2 + H2O

Balancing the Oxidation Half-Reaction

In the oxidation half-reaction, the element V is being oxidized from an oxidation state of 0 to +5 in V2O5. To balance the oxidation half-reaction, we need to ensure that the number of atoms of each element and the total charge are the same on both sides.

The oxidation half-reaction can be written as:

V → V2O5

To balance the number of atoms, we need to add coefficients in front of the species involved. Let's start by balancing the number of V atoms:

2V → V2O5

Now, let's balance the oxygen atoms by adding water (H2O) to the right side:

2V → V2O5 + 5H2O

Next, let's balance the hydrogen atoms by adding H+ ions to the left side:

2V + 10H+ → V2O5 + 5H2O

Finally, let's balance the charges by adding electrons (e-) to the left side:

2V + 10H+ + 5e- → V2O5 + 5H2O

The oxidation half-reaction is now balanced.

Balancing the Reduction Half-Reaction

In the reduction half-reaction, the element N in HNO3 is being reduced from an oxidation state of +5 to +4 in NO2. To balance the reduction half-reaction, we need to ensure that the number of atoms of each element and the total charge are the same on both sides.

The reduction half-reaction can be written as:

HNO3 → NO2 + H2O

To balance the number of atoms, we need to add coefficients in front of the species involved. Let's start by balancing the nitrogen atoms:

HNO3 → NO2 + H2O

Next, let's balance the oxygen atoms by adding water (H2O) to the left side:

HNO3 + H2O → NO2 + H2O

Finally, let's balance the hydrogen atoms by adding H+ ions to the left side:

HNO3 + H2O + 2H+ → NO2 + H2O

The reduction half-reaction is now balanced.

Combining the Half-Reactions

To combine the oxidation and reduction half-reactions, we need to ensure that the number of electrons lost in the oxidation half-reaction is equal to the number of electrons gained in the reduction half-reaction.

The oxidation half-reaction is:

2V + 10H+ + 5e- → V2O5 + 5H2O

The reduction half-reaction is:

HNO3 + H2O + 2H+ → NO2 + H2O

To balance the electrons, we need to multiply the oxidation half-reaction by 2:

4V + 20H+ + 10e- → 2V2O5 + 10H2O

Now, the number of electrons lost in the oxidation half-reaction (10e-) is equal to the number of electrons gained in the reduction half-reaction (10e-).

Final Balanced Equation

Combining the balanced oxidation and reduction half-reactions, we get the final balanced equation:

4V + 20H+ + 10e- + HNO3 + H2O + 2H+ → 2V2O5 + 10H2O + NO2 + H2O

Simplifying the equation and removing the excess water molecules, we get:

4V + 20H+ + HNO3 → 2V2O5 + NO2 + 11H2O

Therefore, the balanced equation using the electron balance method is:

4V + 20H+ + HNO3 = 2V2O5 + NO2 + 11H2O

In this equation, V is the oxidizing agent (the substance that gets reduced) and HNO3 is the reducing agent (the substance that gets oxidized).

I hope this helps! Let me know if you have any further questions.