Question

С помощью метода электронного баланса подберите коэффициенты в уравнениях окислительно-восстановительных реакций: 1. NO2+S= N2+SO2 2. NO2+C= N2 +CO2 3. NO2 +P=N2+P2O5 4. NO2+SO2=SO3+NO3

Answer 1

2NO2+2S=N2+2SO2
2N(+4) +8e= N2(0) 1. в-ие
ок-ль
S(0). -4e = S(+4). 2. ок-ие
в-ль

2NO2+2C=N2+2CO2
2N(+4) +8e=N2(0). 1. в-ие
ок-ль
C(0). -4e = C(+4) 2. ок-ие
в-ль

10NO2+8P=5N2+4P2O5
2N(+4)+8e =N2(0). 5. в-ие
ок-ль
2P(0) -10e =2P(+5). 4. ок-ие
в-ль

в последнем NO3 такого нет

Answer 2

Balancing Redox Reactions using the Electron Balance Method

To balance the given redox reactions using the electron balance method, we need to follow a step-by-step process. The electron balance method involves balancing the number of electrons transferred in the half-reactions to ensure that the total number of electrons gained equals the total number of electrons lost.

Let's balance each of the given reactions one by one:

1. NO2 + S = N2 + SO2

To balance this equation, we need to assign oxidation numbers to each element and identify the species being oxidized and reduced.

The oxidation state of oxygen (O) is usually -2, and the oxidation state of nitrogen (N) is usually -3. Therefore, the oxidation state of nitrogen in NO2 is +4.

The oxidation state of sulfur (S) is usually -2. Therefore, the oxidation state of sulfur in SO2 is +4.

Now, let's balance the equation:

Step 1: Write the unbalanced equation:

NO2 + S = N2 + SO2

Step 2: Separate the equation into two half-reactions, one for oxidation and one for reduction:

Oxidation half-reaction: NO2 → N2 Reduction half-reaction: S → SO2

Step 3: Balance the atoms other than oxygen and hydrogen in each half-reaction:

Oxidation half-reaction: 2NO2 → N2 Reduction half-reaction: S → SO2

Step 4: Balance the oxygen atoms by adding water (H2O) molecules to the side that needs more oxygen:

Oxidation half-reaction: 2NO2 → N2 + 2H2O Reduction half-reaction: S → SO2 + 2H2O

Step 5: Balance the hydrogen atoms by adding hydrogen ions (H+) to the side that needs more hydrogen:

Oxidation half-reaction: 2NO2 + 4H+ → N2 + 2H2O Reduction half-reaction: S → SO2 + 2H2O

Step 6: Balance the charges by adding electrons (e-) to the side that needs more charge:

Oxidation half-reaction: 2NO2 + 4H+ + 4e- → N2 + 2H2O Reduction half-reaction: S → SO2 + 2H2O

Step 7: Multiply the half-reactions by appropriate coefficients to make the number of electrons gained equal the number of electrons lost:

Oxidation half-reaction: 2NO2 + 4H+ + 4e- → N2 + 2H2O Reduction half-reaction: 4S → 4SO2 + 8H2O

Step 8: Add the balanced half-reactions together:

2NO2 + 4H+ + 4e- + 4S → N2 + 2H2O + 4SO2 + 8H2O

Simplifying the equation:

2NO2 + 4H+ + 4S → N2 + 10H2O + 4SO2

Therefore, the balanced equation is:

2NO2 + 4H+ + 4S = N2 + 10H2O + 4SO2 [[1]]

2. NO2 + C = N2 + CO2

To balance this equation, we follow the same steps as above:

Step 1: Write the unbalanced equation:

NO2 + C = N2 + CO2

Step 2: Separate the equation into two half-reactions:

Oxidation half-reaction: NO2 → N2 Reduction half-reaction: C → CO2

Step 3: Balance the atoms other than oxygen and hydrogen in each half-reaction:

Oxidation half-reaction: 2NO2 → N2 Reduction half-reaction: C → CO2

Step 4: Balance the oxygen atoms:

Oxidation half-reaction: 2NO2 → N2 + 2O2 Reduction half-reaction: C → CO2 + O2

Step 5: Balance the hydrogen atoms:

Oxidation half-reaction: 2NO2 → N2 + 2O2 Reduction half-reaction: C + O2 → CO2 + O2

Step 6: Balance the charges:

Oxidation half-reaction: 2NO2 → N2 + 2O2 + 4e- Reduction half-reaction: C + O2 + 4e- → CO2 + O2

Step 7: Multiply the half-reactions by appropriate coefficients:

Oxidation half-reaction: 2NO2 → N2 + 2O2 + 4e- Reduction half-reaction: 2C + 2O2 + 8e- → 2CO2 + 2O2

Step 8: Add the balanced half-reactions together:

2NO2 + 2C + 2O2 + 4e- + 8e- → N2 + 2O2 + 4CO2 + 2O2

Simplifying the equation:

2NO2 + 2C + 10O2 → N2 + 6CO2

Therefore, the balanced equation is:

2NO2 + 2C + 10O2 = N2 + 6CO2 [[2]]

3. NO2 + P = N2 + P2O5

To balance this equation, we follow the same steps as above:

Step 1: Write the unbalanced equation:

NO2 + P = N2 + P2O5

Step 2: Separate the equation into two half-reactions:

Oxidation half-reaction: NO2 → N2 Reduction half-reaction: P → P2O5

Step 3: Balance the atoms other than oxygen and hydrogen in each half-reaction:

Oxidation half-reaction: 2NO2 → N2 Reduction half-reaction: P → P2O5

Step 4: Balance the oxygen atoms:

Oxidation half-reaction: 2NO2 → N2 + 2O2 Reduction half-reaction: P → P2O5 + O2

Step 5: Balance the hydrogen atoms:

Oxidation half-reaction: 2NO2 → N2 + 2O2 Reduction half-reaction: P + O2 → P2O5 + O2

Step 6: Balance the charges:

Oxidation half-reaction: 2NO2 → N2 + 2O2 + 4e- Reduction half-reaction: P + O2 + 4e- → P2O5 + O2

Step 7: Multiply the half-reactions by appropriate coefficients:

Oxidation half-reaction: 2NO2 → N2 + 2O2 + 4e- Reduction half-reaction: 4P + 4O2 + 16e- → 4P2O5 + 4O2

Step 8: Add the balanced half-reactions together:

2NO2 + 4P + 4O2 + 4e- + 16e- → N2 + 2O2 + 4P2O5 + 4O2

Simplifying the equation:

2NO2 + 4P + 20O2 → N2 + 8P2O5

Therefore, the balanced equation is:

2NO2 + 4P + 20O2 = N2 + 8P2O5 [[3]]

4. NO2 + SO2 = SO3 + NO3

To balance this equation, we follow the same steps as above:

Step 1: Write the unbalanced equation:

NO2 + SO2 = SO3 + NO3

Step 2: Separate the equation into two half-reactions:

Oxidation half-reaction: NO2 → NO3 Reduction half-reaction: SO2 → SO3

Step 3: Balance the atoms other than oxygen and hydrogen in each half-reaction:

Oxidation half-reaction: 2NO2 → 2NO3 Reduction half-reaction: SO2 → SO3

Step 4: Balance the oxygen atoms:

Oxidation half-reaction: 2NO2 → 2NO3 + O2 Reduction half-reaction: SO2 → SO3

Step 5: Balance the hydrogen atoms:

Oxidation half-reaction: 2NO2 → 2NO3 + O2 Reduction half-reaction: SO2 + H2O → SO3

Step 6: Balance the charges:

Oxidation half-reaction: 2NO2 + 2e- → 2NO3 + O2 Reduction half-reaction: SO2 + H2O + 2e- → SO3

Step 7: Multiply the half-reactions by appropriate coefficients:

Oxidation half-reaction: 2NO2 + 2e- → 2NO3 + O2 Reduction half-reaction: 2SO2 + 2H2O + 4e- → 2SO3

Step 8: Add the balanced half-reactions together:

2NO2 + 2SO2 + 2H2O