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For the electro chemical cell M|M2+ || X|X2- If Eb0(M2+/M) = 0.46 V and Eb0(X/X2-) = -0.34 V. Which of the following is correct ?

1. Ecell = -0.80 V
2. M + X M2+ + X2- is a spontaneous reaction
3. M2+ + X2- M + X is a spontaneous reaction
4. Ecell = 0.80 V

Correct answer: M2+ + X2- M + X is a spontaneous reaction

Solution

The reaction M2+ + X2- → M + X is spontaneous because the standard cell potential (Ecell) is positive, indicating that the overall reaction can occur without external energy. This is determined by calculating Ecell using the given standard reduction potentials, which results in a positive value, confirming spontaneity.

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