Units for lnQ


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JamieVu_2C
Posts: 108
Joined: Thu Jul 25, 2019 12:16 am

Units for lnQ

Postby JamieVu_2C » Mon Mar 02, 2020 5:06 pm

For some problems where you have to calculate the cell potential using the Nernst equation, the solutions manual substitutes concentrations for aqueous species and partial pressures for gases into Q for lnQ. Don't you have to convert the units so that the species in Q are uniformly either in M or atm/bar? Or, can you leave the species in their standard states as given without conversion?

Jack Riley 4f
Posts: 100
Joined: Sat Aug 24, 2019 12:17 am

Re: Units for lnQ

Postby Jack Riley 4f » Mon Mar 02, 2020 6:08 pm

Q is a ratio so it has no units because they cancel out

Amy Pham 1D
Posts: 103
Joined: Fri Aug 09, 2019 12:15 am

Re: Units for lnQ

Postby Amy Pham 1D » Mon Mar 02, 2020 6:20 pm

As long as both the top and bottom components of the Q ratio have the same units, there is no need to convert as they will cancel out and fit into the logarithm as such.


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