Question

С+Na2Cr2O7->Cr2O3+Na2O+CO как это решить методом электронного баланса

Answer 1

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Answer 2

Balancing the Equation using the Electron Balance Method

To balance the equation Na2Cr2O7 -> Cr2O3 + Na2O + CO 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.

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

Oxidation Half-Reaction: Na2Cr2O7 -> Cr2O3

In this half-reaction, chromium (Cr) is being reduced from a +6 oxidation state in Na2Cr2O7 to a +3 oxidation state in Cr2O3. To balance the oxidation half-reaction, we need to determine the number of electrons lost.

The oxidation state of chromium decreases by 3, indicating that 3 electrons are lost. Therefore, the oxidation half-reaction is:

Na2Cr2O7 -> Cr2O3 + 3e-

Reduction Half-Reaction: Na2Cr2O7 -> Na2O + CO

In this half-reaction, the chromium (Cr) in Na2Cr2O7 is reduced to a lower oxidation state, resulting in the formation of Na2O and CO. To balance the reduction half-reaction, we need to determine the number of electrons gained.

To balance the reduction half-reaction, we need to assign oxidation states to each element. In Na2Cr2O7, the oxidation state of chromium is +6, and in Na2O, the oxidation state of oxygen is -2. Therefore, the oxidation state of carbon in CO must be +4.

The oxidation state of carbon increases by 2, indicating that 2 electrons are gained. Therefore, the reduction half-reaction is:

Na2Cr2O7 + 2e- -> Na2O + CO

Now, we can balance the number of electrons lost and gained in both half-reactions by multiplying the oxidation half-reaction by 2 and the reduction half-reaction by 3:

2(Na2Cr2O7) -> 2(Cr2O3) + 6e- 3(Na2Cr2O7) + 6e- -> 3(Na2O) + 3(CO)

Finally, we can combine the two half-reactions and cancel out the electrons:

2(Na2Cr2O7) + 3(Na2Cr2O7) + 6e- -> 2(Cr2O3) + 3(Na2O) + 3(CO) + 6e-

Simplifying the equation, we get:

5(Na2Cr2O7) -> 2(Cr2O3) + 3(Na2O) + 3(CO)

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

5Na2Cr2O7 -> 2Cr2O3 + 3Na2O + 3CO.

Please note that the above explanation is based on the information available from the search results.