Question

Расставьте коэффициенты методом электронного баланса, укажите окислитель и восстановитель, процессы окисления и восстановления: Al + HNO3(конц) -> NO2 + Al(NO3)3 +H2O

Answer 1

 6HNO3 + Al = Al(NO3)2 + 3NO2 + 3H2O     Al - восстановитель

Al(0) - 3e = Al (+3)   | 1                                           HNO3 - окислитель

N (+5) +1e = N (+4) | 3

Answer 2

Balancing the Chemical Equation:

To balance the chemical equation Al + HNO3(conc) -> NO2 + Al(NO3)3 + H2O using the method of electronic balance, we need to follow these steps:

1. Write down the unbalanced equation. 2. Identify the oxidation states of each element. 3. Balance the atoms that are undergoing oxidation and reduction. 4. Balance the remaining atoms. 5. Finally, balance the charges by adding electrons.

Let's proceed with balancing the given chemical equation.

Balancing the Chemical Equation:

The unbalanced chemical equation is: Al + HNO3(conc) -> NO2 + Al(NO3)3 + H2O

Identifying the Oxidation States:

- The oxidation state of Al is 0. - The oxidation state of H in HNO3 is +1. - The oxidation state of N in HNO3 is +5. - The oxidation state of O in HNO3 is -2.

Balancing the Equation:

1. Balance the atoms undergoing oxidation and reduction: - The oxidation state of N in NO2 is +4, and in HNO3 is +5. Therefore, N is undergoing reduction. - The oxidation state of Al in Al(NO3)3 is +3, and in Al is 0. Therefore, Al is undergoing oxidation.

2. Balance the atoms undergoing oxidation and reduction: - Multiply Al by 4 and HNO3 by 6 to balance Al and N atoms.

The balanced equation is: 4Al + 6HNO3(conc) -> 4NO2 + 4Al(NO3)3 + 3H2O

Identifying the Oxidizing and Reducing Agents:

- The oxidizing agent is the substance that gets reduced, which is HNO3 in this case. - The reducing agent is the substance that gets oxidized, which is Al in this case.

Processes of Oxidation and Reduction:

- Oxidation: The process of oxidation occurs to the aluminum (Al) as it loses electrons and increases its oxidation state from 0 to +3 in Al(NO3)3. - Reduction: The process of reduction occurs to the nitric acid (HNO3) as it gains electrons and decreases the oxidation state of nitrogen from +5 to +4 in NO2.

This completes the balancing of the chemical equation using the method of electronic balance, along with identifying the oxidizing and reducing agents and the processes of oxidation and reduction.