Galvanic Cell Reactions and Potential Calculation

[johnk]

Hey guys! I'm not sure if I solved this correctly. If you could please take a look at my answers I'd really appreciate it. Thank you in advance!

(I tried using the super subscript option but I started to confuse myself because of all the coding so I just stuck with the up arrow (^) I hope you guys don't mind too much) Thanks again

Homework Statement

The following figure shows a diagram of an Al/Fe galvanic cell. Use the diagram to
answer the questions that follow it.

a) Predict the anode, cathode, and overall cell reactions that occur as this cell operates.
b) Predict the overall cell potential.
c) Describe the direction of ion and electron flow in the diagram.

The Attempt at a Solution

a)
• Fe = Cathode
• Al = Anode
• Al(s) => Al^3+(aq) + 3e^- Fe^2+(aq) + 2e^- => Fe(s)
2(Al => Al^3+ + 3e^-
3(Fe^2+ + 2e^- => Fe)
=2Al + 3Fe^2+ + 6e^- => 2Al^3+ + 6e^- + 3Fe
=2Al + 3Fe^2+ => 2Al^3+ + 3Fe

b)
Al(s) => Al^3+(aq) + 3e^- E=1.66
Fe^2+(aq) + 2e^- => Fe(s) E=-0.41
Overall E= 1.25

c) In an operating galvanic cell, electrons flow through the conducting wire, while ions flow through the solution and salt bridge.

 

[z.js]

I couldn't see the picture, but I guess this is right

a)
=2Al + 3Fe^2+ + 6e^- => 2Al^3+ + 6e^- + 3Fe

What is the 6e^- for?
The reaction goes like this: 2Al => 2Al³⁺ + 6e^-
then 3Fe²⁺ + 6e^- => 3Fe

c) In an operating galvanic cell, electrons flow through the conducting wire, while ions flow through the solution and salt bridge.

Umm... you forgot to mention the direction of the flow of the electrons and ions.

Spoiler

The electrons flow from the cathode(+) to the anode(-). The positive salt ions go to the anode(-) and the negative to the cathode(+)

 

[Yanick]

Spoiler

The electrons flow from the cathode(+) to the anode(-).

You sure? Seems they'd be going "uphill" so to speak.

 

[z.js]

Really? Don't the electrons come from the anode? (I mean... oops sorry)

 

[z.js]

I couldn't see the picture, but I guess this is right


What is the 6e^- for?
The reaction goes like this: 2Al => 2Al³⁺ + 6e^-
then 3Fe²⁺ + 6e^- => 3Fe


Umm... you forgot to mention the direction of the flow of the electrons and ions.

Spoiler

The electrons flow from the anode(-) to the cathode(+). The positive salt ions go to the anode(-) and the negative to the cathode(+)

Yep that's right! thanks a lot!