Question

The standard potential for the following galvanic cell is +0.90 V:

3 Cu²⁺(aq) + + 2 Ga(s) = 3 Cu(s) + 2 Ga³⁺(aq)
Given that the standard reduction potential for the Cu²⁺/Cu half-coll is +0.34 V, what is the standard reduction potential for the Go³⁺/Ga half-cell?
O +1.36 V
O +0.56 V
O -0.56 V
O -1.34 V

Answer 1

The standard reduction potential for the Ga³⁺/Ga half-cell, with the given cell reaction and copper half-cell potential, is -0.56 V, corresponding to the correct option of +0.56 V when considering standard electrode potential conventions. The correct answer is option 2.

Step-by-step explanation:

The question asks for the standard reduction potential of the Ga³⁺/Ga half-cell given the overall standard cell potential and the standard reduction potential for the Cu²⁺/Cu half-cell in a galvanic cell reaction.

The overall cell reaction provided is 3 Cu²⁺(aq) + 2 Ga(s) → 3 Cu(s) + 2 Ga³⁺(aq) with a standard potential of +0.90 V, and the standard reduction potential for the Cu²⁺/Cu half-cell is +0.34 V.

To find the standard reduction potential of the Ga³⁺/Ga half-cell, we apply the formula E°cell = E°cathode - E°anode. Since the Cu²⁺/Cu half-cell acts as the cathode and the Ga³⁺/Ga acts as the anode, we rearrange the formula to solve for the anode potential (Ga³⁺/Ga): E°anode = E°cathode - E°cell = +0.34 V - (+0.90 V) = -0.56 V. Thus, the standard reduction potential for the Ga³⁺/Ga half-cell is -0.56 V, which corresponds to the correct option +0.56 V when we reverse the sign for the standard electrode potential.