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Statement : If two half reaction with el...

Statement : If two half reaction with electrode potential `E_(1)^(@)` and `E_(2)^(@)` gives a third reaction then,
`DeltaG_(3)^(@) = DeltaG_(1)^(@) + DeltaG_(2)^(@)`
Explanation : `E_(3)^(@) = E_(1)^(@) + E_(2)^(@)`

A

STATEMENT-1 is True, STATEMENT-2 is True, STATEMENT -2 is correct explanation for STATEMENT-1

B

STATEMENT 1 is True, STATEMENT-2 Is True, STATEMENT -2 is NOT a correct explanation for STATEMENT-1

C

STATEMENT - 1 is True, STATEMENT-2 is False

D

STATEMENT-1 is False, STATEMENT-2 is True

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question, we need to analyze the statements regarding the relationship between the Gibbs free energy change (ΔG) and the standard electrode potentials (E) of half-reactions. ### Step-by-Step Solution: 1. **Understanding the Gibbs Free Energy Change (ΔG)**: - The Gibbs free energy change (ΔG) is a thermodynamic potential that can predict the direction of chemical reactions. It is an extensive property, meaning it depends on the amount of substance present. - For a reaction, the relationship between ΔG and the standard electrode potential (E) is given by the equation: \[ \Delta G = -nFE \] where: - \( n \) = number of moles of electrons transferred, - \( F \) = Faraday's constant (approximately 96485 C/mol), - \( E \) = standard electrode potential. 2. **Applying the Relationship to Half-Reactions**: - For two half-reactions with standard electrode potentials \( E_1^{\circ} \) and \( E_2^{\circ} \): - The Gibbs free energy changes for these half-reactions can be expressed as: \[ \Delta G_1^{\circ} = -n_1FE_1^{\circ} \] \[ \Delta G_2^{\circ} = -n_2FE_2^{\circ} \] 3. **Combining the Half-Reactions**: - When these two half-reactions are combined to form a third reaction, the Gibbs free energy change for the overall reaction (ΔG3) can be expressed as: \[ \Delta G_3^{\circ} = \Delta G_1^{\circ} + \Delta G_2^{\circ} \] - This is valid because ΔG is an extensive property and can be added for the overall reaction. 4. **Analyzing the Electrode Potentials**: - The standard electrode potential for the overall reaction (E3) is related to the individual potentials: \[ E_3^{\circ} \neq E_1^{\circ} + E_2^{\circ} \] - This is because electrode potential is an intensive property, which means it does not depend on the amount of material and cannot be simply added. 5. **Conclusion**: - The first statement regarding ΔG is correct: \[ \Delta G_3^{\circ} = \Delta G_1^{\circ} + \Delta G_2^{\circ} \] - The second statement regarding the electrode potentials is incorrect: \[ E_3^{\circ} \neq E_1^{\circ} + E_2^{\circ} \] ### Final Answer: - The correct option is that the first statement is true, and the second statement is false.
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