Question

A galvanic cell is constructed using chromium and tin. Based on the standard reduction potentials shown, which statement correctly describes the reaction that occurs in the cell?
Cr3+(aq) + 3e– ==> Cr(s) Eº = –0.74 V
Sn2+(aq) + 2e– ==> Sn(s) Eº = –0.14 V

Answer 1

Have you used "activity tables" before?

It's the same thing, except that activity tables are qualitative while reduction potentials are quantitative.

On an activity table, a more reactive metal will be oxidized by a less reactive one. Similarly, a metal with a \(\sf lower\) (more negative) reduction potential will be oxidized by a metal while a \(\sf higher\) reduction potential. The way you are to set up this cell is for it to be spontaneous, which can only happen if the electric potential of the cell is positive.

First determine what is oxidized and what is reduced from the reduction potentials and write the equation for the cell so the sum of the potentials is positive.

Answer 2

potential = -0.14 - (-0.74) @aaronq

Answer 3

@JoannaBlackwelder

Answer 4

@Somy @KL-RC

Answer 5

@iambatman @Haseeb96

Answer 6

I don't think it is c because the chromium is the oxidized species according to their reduction potentials.

Answer 7

I also don't think it is b because galvanic cells react without adding an outside source of current.

Answer 8

Am I making sense so far?

Answer 9

yep I thought the same about B and I see what you're saying about C @JoannaBlackwelder

Answer 10

Cool. Also, plating occurs at the reduced element, so, the tin electrode (cathode) should gain mass, not lose it. So, d is out.

Answer 11

Can you tell me why a makes most sense?

Answer 12

wait why is D out??

Answer 13

Tin is reduced and plating occurs at the cathode (or reduced species).

Answer 14

So the cathode gains mass.

Answer 15

ohhh got it ok

Answer 16

thanks!

Answer 17

:D No worries