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Nicoline Breytenbach 3D
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Postby Nicoline Breytenbach 3D » Sun Sep 30, 2018 9:45 pm

In some places I see grams per mole written as (g/mol) and other places as (g.mol^-1). I'm pretty sure they mean the same thing but I just want to confirm? Also is there a reason to use one notation rather than the other?

Saman Andalib 1H
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Re: Grams/mole

Postby Saman Andalib 1H » Sun Sep 30, 2018 9:49 pm

In short, yes, the two notations mean the exact same thing. Anything raised to the negative 1st power will always go to the denominator, making the two short-hands directly interchangeable. There have been no instances in which I have seen that there makes a significant difference when one notation is used over the other.

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Re: Grams/mole

Postby AustinGrove3B » Sun Sep 30, 2018 9:58 pm

Using g mol^ -1 can sometimes make your math a lot cleaner to look at, compared to writing it as ___ g / ___mol. If you divide g mol^-1 by another g mol^-1, it avoids having to write fractions inside of a fraction. Technically, doing that would be correct, but it would be really hard to interpret.

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Re: Grams/mole

Postby LaurenJuul_1B » Mon Oct 01, 2018 1:31 am

Both notations are the same! It is more of a personal preference on which to use. I, for example, prefer g/mol because I am used to writing units that way. In g.mol^-1, the -1 just means that the mole is raised to the negative first power, meaning it is in the denominator of the fraction just like you see in the notation g/mol.

Nathan Tran 4K
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Re: Grams/mole

Postby Nathan Tran 4K » Mon Oct 01, 2018 9:41 am

Yes, they are the same notation. Negative powers just indicate that the exponent will appear in the denominator. For example, x^(-1) is simply 1/(x)^1. Another way to think of it is looking at the term as the reciprocal of the absolute value of the exponent. Because the grams are multiplied by (moles)^(-1), the grams will appear in the numerator while the moles will appear in the denominator.

Katie Sy 1L
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Re: Grams/mole

Postby Katie Sy 1L » Mon Oct 01, 2018 11:37 am

Yes these two notations mean the same thing. I believe it is a personal preference for which version to use. In some cases, it might be easier to type one out than the other. The negative 1 in the numerator means it will move to the denominator.

Raymond Ko 1H
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Re: Grams/mole

Postby Raymond Ko 1H » Mon Oct 01, 2018 11:42 am

Both notations essentially have the same meaning. Personally, I use the g/mol notation when I'm setting up stoichiometric calculations so that I can see the conversion factors clearly. However, when not performing those calculations such as when writing an answer or answering a question in paragraph format, g*mol^-1 definitely looks a lot neater and would be less misleading to whoever reads it.

George Ghaly 2L
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Re: Grams/mole

Postby George Ghaly 2L » Mon Oct 01, 2018 6:17 pm

Both g/mol and gmol^-1 represent grams divided by moles while the latter just uses textbook notation in order to represent that grams is being divided by moles in a more comprehensive way. Feel free to use either or as they both represent the same thing.

Veronica Soliman 4H
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Re: Grams/mole

Postby Veronica Soliman 4H » Mon Oct 01, 2018 6:26 pm

In short, yes both of these mean the same thing. It is a large textbook and has been edited several times before publishing, therefore, different authors may have changed the notation. They still mean the same thing. Hope this helps.

Vicky Lu 1L
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Re: Grams/mole

Postby Vicky Lu 1L » Mon Oct 01, 2018 10:08 pm

g/mol and g.mol^-1 are two different notation but they mean the same things. the ^-1 denotes that mol will be in the denominator. I like to use g/mol to see it fully written out and for it to already be in that form when I use it to solve problems.

Aleeque Marselian 1A
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Re: Grams/mole

Postby Aleeque Marselian 1A » Mon Oct 01, 2018 10:23 pm

Both notations are virtually the same because g.mol^-1 is rewritten as g/mol when the negative exponent is moved to the denominator in order to make it positive. Therefore, the use of one of the notations is based on personal preference. Hope this helps!!

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Re: Grams/mole

Postby Katie_Duong_1D » Wed Oct 03, 2018 2:34 pm


g/mol and g * mol^-1 mean the same thing. They are just written out a little differently. g/mol is dividing unit mass (g) by unit mole (mol). g * mol^-1 is also a division, but written as a multiplication. Mol is raised to the power of -1, so mol is treated as a denominator.

I personally like to use g/mol because it takes up less space than g*mol^-1.

Karla_Ocampo 4E
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Re: Grams/mole

Postby Karla_Ocampo 4E » Wed Oct 03, 2018 2:57 pm

Thank you for posting this as I was too confused on which to use. However now I know that they have the same meaning but they are just written differently. So, in g.mol ^-1 , the -1 is supposed to be the denominator, which turns out to be the same as g/mol. Really it just comes down to your preference, personally I prefer to use g/mol because I feel it looks better on my notes!

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