If $E _ { \text {catrode } } ^ { \circ }$ = 1.60 V and $E _ { \text {arode } } ^ { \circ }$ = 1.25 V, what is the free energy change for the reaction? Given: Total charge transferred during the reaction is equal to 1.93×10⁵ $\text{C/mol}^{-}$ .

Question

Quizplus · Accepted Answer

The free energy change, ∆𝐺, can be calculated using the equation:

∆𝐺 = -𝑛𝑆𝑇𝑙𝑛(Q)

Where 𝑛 is the number of moles of electrons transferred during the reaction, S is the molar entropy of electrons, T is temperature, and Q is the reaction quotient. The equation can be simplified in terms of cell potential:

∆𝐺 = -nF𝐸°

Where F is the Faraday constant (96,485 C/mol) and E° is the standard cell potential.

In this case, the number of moles of electrons transferred during the reaction is given as 1.93×10^-1 C/mol. Since each mol of electrons corresponds to one mol of the reaction, we can take n = 1. Thus,

∆𝐺 = -nF𝐸°
= -(1 mol)(96,485 C/mol)(1.60 V - 1.25 V)
= -67,585 J/mol
= -67.6 kJ/mol (since 1 kJ = 1000 J)

Thus, the answer is C.

If Ecatrode ∘E _ { \text {catrode } } ^ { \circ }Ecatrode ∘​

If $E _ { \text {catrode } } ^ { \circ }$