log or ln

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log or ln

Postby KBELTRAMI_1E » Wed Feb 26, 2020 10:35 am

For the Nernst equation I've seen both ln and log used applied to Q and I'm confused as to which is correct or if they are used in different situations. Khan academy videos on Youtube seem to strictly use log but in lecture and discussion we've used ln.

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Re: log or ln

Postby AArmellini_1I » Wed Feb 26, 2020 10:59 am

You want to use log when dealing with pH and [H+] [OH-] concentrations

Sean Cheah 1E
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Re: log or ln

Postby Sean Cheah 1E » Wed Feb 26, 2020 11:05 am

Strictly speaking, you can use either as long as you are able to calculate the Q for the reaction. It is often more convenient to use log for problems involving pH because pH = -log[H+]. Do note that that you must multiply the logarithmic term by a factor of 1/log(e) = ~2.303 when you use the log equation instead of the regular ln equation.

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Re: log or ln

Postby 705302428 » Wed Feb 26, 2020 12:34 pm

You can use either. They mean the same thing.

Asha Agarwal 1E
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Re: log or ln

Postby Asha Agarwal 1E » Wed Feb 26, 2020 1:07 pm

Both can be used there is just a necessary conversion factor required to convert from ln to log.

Zoe Gleason 4F
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Joined: Tue Jul 23, 2019 12:15 am

Re: log or ln

Postby Zoe Gleason 4F » Wed Feb 26, 2020 1:13 pm

You can use either but the log one is more useful when you have to solve for pH or have the pH given in the question, because you are then able to leave it in log[H+] form.

Matthew ILG 1L
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Re: log or ln

Postby Matthew ILG 1L » Wed Feb 26, 2020 3:59 pm

You are able to use either the log or ln, and I believe Dr. Lavelle provided an equation using each. However, he also stated that log is often preferred by scientists because pH also uses log.

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