Question

A voltaic cell that uses the reaction
Tl3+(aq)+2Cr2+(aq)→Tl+(aq)+2Cr3+(aq)
has a measured standard cell potential of +1.19 V.

Part A

Write the two half-cell reactions.

Express your answer as a chemical equation. Identify all of the phases in your answer

Part B

Express your answer as a chemical equation. Identify all of the phases in your answer.

Part C

By using data from Appendix E, determine E∘red for the reduction of Tl3+(aq) to Tl+(aq).

Express your answer using two significant figures.

Sketch the voltaic cell, label the anode and cathode, and indicate the direction of electron flow.

Drag the labels to the appropriate targets. (anions, cations, anode, cathode, e- down, e-upwards to the right)

Answer 1

Sol :-

Part.A.

Half cell reactions:

At Anode (oxidation) :    Cr²⁺ (aq) ----------->  Cr³⁺ (aq) + e^-

At cathode (reduction) : Tl³⁺(aq) + 2e^- ------------>  Tl⁺(aq)

Part.B :-

From standard reduction table we get, E⁰_Cr3+/Cr2+ = -0.42 V

E⁰_cell = +1.19 V

We know, E⁰_cell = E⁰_cathode - E⁰_anode

So, E⁰_cell = +1.19 V = E⁰_Tl3+/Tl+ - E⁰_Cr3+/Cr2+ = E⁰_Tl3+/Tl+ - (-0.42 V)

E⁰_Tl3+/Tl+ = 1.19-0.42 = 0.77 V

Part.C :-