calculating Q


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805383532
Posts: 53
Joined: Thu Jul 11, 2019 12:16 am

calculating Q

Postby 805383532 » Sun Mar 08, 2020 8:10 pm

When finding Q in the nernst equation, is it always [cathode]/[anode] or is it [anode]/[cathode] ?

Bilal Pandit 1J
Posts: 98
Joined: Wed Sep 11, 2019 12:16 am

Re: calculating Q

Postby Bilal Pandit 1J » Sun Mar 08, 2020 8:11 pm

It can be determined by the overall cell reaction, with the concentrations plugged in for Q (products over reactants)

Sjeffrey_1C
Posts: 108
Joined: Wed Feb 20, 2019 12:17 am

Re: calculating Q

Postby Sjeffrey_1C » Sun Mar 08, 2020 8:20 pm

I believe its [anode]/[cathode]

Isabella Dal Porto 1H
Posts: 100
Joined: Fri Aug 30, 2019 12:16 am

Re: calculating Q

Postby Isabella Dal Porto 1H » Sun Mar 08, 2020 8:20 pm

I believe that it is [anode]/[cathode].

J_CHEN 4I
Posts: 54
Joined: Tue Nov 14, 2017 3:01 am

Re: calculating Q

Postby J_CHEN 4I » Sun Mar 08, 2020 8:25 pm

Q is [Products]/[Reactants] so it depends on the chemical equation.

AronCainBayot2K
Posts: 101
Joined: Fri Aug 30, 2019 12:17 am

Re: calculating Q

Postby AronCainBayot2K » Sun Mar 08, 2020 9:13 pm

Q should be anode/cathode.

Bryce Barbee
Posts: 103
Joined: Wed Sep 18, 2019 12:20 am

Re: calculating Q

Postby Bryce Barbee » Sun Mar 08, 2020 9:14 pm

I was told that it is anode/cathode when using this equation.

saigorijavolu2k
Posts: 108
Joined: Sat Sep 28, 2019 12:15 am

Re: calculating Q

Postby saigorijavolu2k » Sun Mar 08, 2020 9:26 pm

anode/cathode

anode looses mass, cathode gains mass

Vivianvelazquez_1J
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Been upvoted: 1 time

Re: calculating Q

Postby Vivianvelazquez_1J » Sun Mar 08, 2020 9:28 pm

It should be Anode over Cathode.

Trent Yamamoto 2J
Posts: 111
Joined: Sat Aug 17, 2019 12:18 am

Re: calculating Q

Postby Trent Yamamoto 2J » Tue Mar 10, 2020 8:27 pm

Q= [anode]/[cathode]

Sean Cheah 1E
Posts: 105
Joined: Wed Sep 18, 2019 12:20 am

Re: calculating Q

Postby Sean Cheah 1E » Wed Mar 11, 2020 3:37 pm

Q is a reaction quotient, which means that for most redox reactions, as long as you have the balanced equation, it should look identical to the equilibrium expression (with appropriate exponents to match the coefficients in the balanced equation). The equilibrium expression always puts products in the numerator and reactants in the denominator.

For example, looking at the generic redox equation A+(aq) + B (s) --> A(s) + B+(aq), the only concentration on the products' side is [B+] and the only concentration on the reactants' side is [A+]. Note that in this case, A+ is the species being reduced, meaning it is being consumed like a reactant at the cathode. Similarly, B(s) is the species being oxidized, meaning B+ is being produced like a product at the anode. Thus, since the coefficients are all 1 in this case, Q = [B+]/[A+] = [Anode ion]/[Cathode ion].

Alexandra Bartolome 2H
Posts: 102
Joined: Sat Jul 20, 2019 12:17 am

Re: calculating Q

Postby Alexandra Bartolome 2H » Thu Mar 12, 2020 9:24 am

Q = [products]/[reactants] so it would be [anode]/[cathode]

Mariah
Posts: 104
Joined: Fri Aug 02, 2019 12:16 am

Re: calculating Q

Postby Mariah » Thu Mar 12, 2020 9:30 am

I think its easier to think products/reactants.


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