Question

В схеме ОВР расставьте коэффиценты методом электронного баланса, укажите окислитель и востановитель. Cu+HNO3(конц)---->CU(NO3)2+NO2+H2O.

Answer 1

Ответ смотри во вложении

Answer 2

Balancing the Chemical Equation using the Oxidation-Reduction Method

To balance the chemical equation Cu + HNO3(conc) → Cu(NO3)2 + NO2 + H2O using the oxidation-reduction method, we need to identify the oxidation states of each element and then balance the equation by adjusting the coefficients.

1. Identifying the Oxidation States: - The oxidation state of copper (Cu) is 0 in its elemental form. - The oxidation state of nitrogen (N) in HNO3 is +5, and in NO2, it is +4. - The oxidation state of oxygen (O) in HNO3 is -2, and in NO2, it is -2. - The oxidation state of hydrogen (H) is +1 in HNO3 and -1 in H2O.

2. Balancing the Equation: - The unbalanced equation is: Cu + HNO3 → Cu(NO3)2 + NO2 + H2O

3. Determining the Oxidation and Reduction: - Copper (Cu) is oxidized from 0 to +2 in Cu(NO3)2. - Nitrogen (N) is reduced from +5 to +4 in NO2.

4. Balancing the Oxidation and Reduction Half-Reactions: - Oxidation Half-Reaction: Cu → Cu^2+ + 2e^- - Reduction Half-Reaction: 2H^+ + NO3^- + 2e^- → NO2 + H2O

5. Balancing the Number of Electrons Transferred: - To balance the number of electrons transferred, the reduction half-reaction is multiplied by 2: 4H^+ + 2NO3^- + 4e^- → 2NO2 + 2H2O

6. Balancing the Overall Equation: - The balanced equation is: 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O

7. Identifying the Oxidizing and Reducing Agents: - The oxidizing agent is HNO3, which is reduced from +5 to +4. - The reducing agent is Cu, which is oxidized from 0 to +2.

Therefore, the balanced equation using the oxidation-reduction method is: 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O. The oxidizing agent is HNO3, and the reducing agent is Cu.