Test 2 Question 4

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Gwen Peng 1L
Posts: 36
Joined: Sat Jul 22, 2017 3:01 am

Test 2 Question 4

Postby Gwen Peng 1L » Sat Mar 17, 2018 7:41 pm

This question asks to find the standard cell potential of the following:
Cu|Cu2+||Au+|Au
It gives the half reactions:
Cu2+ + 2e- --> Cu E standard= 0.34V
Au+ + 1e- --> Au E standard= 1.69 V
As shown in the cell diagram the Au is the cathode and the Cu is the anode, but you would have to flip the half reaction on Cu since the cell diagram is Cu|Cu2+ meaning you change the sign on the voltage.
So wouldn't you solve by using E standard cell= 1.69 V - (-0.34 V)?
Or would the 0.34 remain positive even though the reaction given is flipped?

RenuChepuru1L
Posts: 58
Joined: Thu Jul 27, 2017 3:00 am

Re: Test 2 Question 4

Postby RenuChepuru1L » Sat Mar 17, 2018 7:47 pm

I think where you're getting confused is E standard= Ecathode-Eanode so if you "flip" the sign you wouldn't subtract again, you'd add

Gwen Peng 1L
Posts: 36
Joined: Sat Jul 22, 2017 3:01 am

Re: Test 2 Question 4

Postby Gwen Peng 1L » Sat Mar 17, 2018 8:57 pm

RenuChepuru1L wrote:I think where you're getting confused is E standard= Ecathode-Eanode so if you "flip" the sign you wouldn't subtract again, you'd add

So since there is a double negative it would be E standard= 1.69 V + 0.34 V, correct?


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