Question

Методом электронного баланса подберите коэффициенты в уровнях окислительно - восстановительных реакциях1) Zn + H2SO4 = ZnSO4 + SO2 + H2O2)Ca + H2O = Ca(OH)2 + H2

Answer 1

В приложении ОВР баланс

Answer 2

Method of Electron Balance for Oxidation-Reduction Reactions

The method of electron balance is a technique used to balance oxidation-reduction (redox) reactions by ensuring that the number of electrons gained in the reduction half-reaction is equal to the number of electrons lost in the oxidation half-reaction. This method involves assigning oxidation numbers to each element in the reaction and then balancing the charges and atoms on both sides of the equation.

Let's apply the method of electron balance to the given reactions:

1) Zn + H2SO4 = ZnSO4 + SO2 + H2O

To balance this equation, we need to assign oxidation numbers to each element:

- In Zn, the oxidation number is 0 since it is an uncombined element. - In H2SO4, the oxidation number of H is +1, the oxidation number of S is +6, and the oxidation number of O is -2. - In ZnSO4, the oxidation number of Zn is +2, the oxidation number of S is +6, and the oxidation number of O is -2. - In SO2, the oxidation number of S is +4 and the oxidation number of O is -2. - In H2O, the oxidation number of H is +1 and the oxidation number of O is -2.

Now, let's balance the equation step by step:

1) Balance the atoms other than hydrogen and oxygen: - The number of Zn atoms on both sides is already balanced. - The number of S atoms on both sides is already balanced. - The number of O atoms on both sides is already balanced.

2) Balance the oxygen atoms by adding water molecules (H2O) to the side that needs more oxygen: - There are 4 oxygen atoms on the right side (in ZnSO4 and SO2), so we need to add 4 H2O molecules to the left side.

The equation now becomes: Zn + H2SO4 = ZnSO4 + SO2 + 4H2O

3) Balance the hydrogen atoms by adding hydrogen ions (H+) to the side that needs more hydrogen: - There are 8 hydrogen atoms on the left side (in H2SO4), so we need to add 8 H+ ions to the right side.

The equation now becomes: Zn + H2SO4 = ZnSO4 + SO2 + 4H2O + 8H+

4) Balance the charges by adding electrons (e-) to the side that needs more negative charge: - The left side has a charge of 0, while the right side has a charge of +8 (from the 8 H+ ions). - To balance the charges, we need to add 8 electrons to the left side.

The equation now becomes: Zn + H2SO4 = ZnSO4 + SO2 + 4H2O + 8H+ + 8e-

5) Finally, check if the number of electrons gained in the reduction half-reaction is equal to the number of electrons lost in the oxidation half-reaction. In this case, the number of electrons gained and lost is already balanced.

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

Zn + H2SO4 = ZnSO4 + SO2 + 4H2O + 8H+ + 8e- [[1]]

Now, let's move on to the second reaction:

2) Ca + H2O = Ca(OH)2 + H2

To balance this equation, we need to assign oxidation numbers to each element:

- In Ca, the oxidation number is 0 since it is an uncombined element. - In H2O, the oxidation number of H is +1 and the oxidation number of O is -2. - In Ca(OH)2, the oxidation number of Ca is +2, the oxidation number of O is -2, and the oxidation number of H is +1.

Now, let's balance the equation step by step:

1) Balance the atoms other than hydrogen and oxygen: - The number of Ca atoms on both sides is already balanced. - The number of O atoms on both sides is already balanced.

2) Balance the hydrogen atoms by adding hydrogen ions (H+) to the side that needs more hydrogen: - There are 2 hydrogen atoms on the right side (in Ca(OH)2), so we need to add 2 H+ ions to the left side.

The equation now becomes: Ca + H2O = Ca(OH)2 + 2H+

3) Balance the charges by adding electrons (e-) to the side that needs more negative charge: - The left side has a charge of 0, while the right side has a charge of +2 (from the 2 H+ ions). - To balance the charges, we need to add 2 electrons to the left side.

The equation now becomes: Ca + H2O = Ca(OH)2 + 2H+ + 2e-

4) Finally, check if the number of electrons gained in the reduction half-reaction is equal to the number of electrons lost in the oxidation half-reaction. In this case, the number of electrons gained and lost is already balanced.

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

Ca + H2O = Ca(OH)2 + 2H+ + 2e- [[2]]

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