## Units for lnQ

$E_{cell} = E_{cell}^{\circ}-\frac{RT}{nF}\ln Q$

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

### Units for lnQ

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

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

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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