Definition of moles [ENDORSED]

Jonghwee Park 1K
Posts: 30
Joined: Fri Apr 06, 2018 11:04 am

Definition of moles

I don't understand how a mole means the number of atoms in something and also always means 6.022 x 10^23 of 'things' at the same time?
Also, why is a mol of carbon different than a mol of hydrogen? Basically, I'm having trouble finding a concrete definition for moles and what it actually means.

Chem_Mod
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Re: Definition of moles

You should find the answer to your question here: viewtopic.php?f=26&t=30535

danielruiz1G
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Joined: Fri Apr 06, 2018 11:04 am

Re: Definition of moles

A mol is a unit of measurement for an amount of a specific substance such as carbon or hydrogen, and they are different because they are completely different chemical substances and Avogadro's number (6.022 x 10^23 mol^-1) is just a constant when converting grams to atomic mass. I hope this helps.

Endri Dis 1J
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Joined: Fri Apr 06, 2018 11:02 am

Re: Definition of moles

You can also think of it for example as having a mole of oxygen means that you have 6.02 x 10^23 atoms of oxygen which weighs 16grams, so how much a mole weighs is dependent on the atom.

AshleyLamba1H
Posts: 30
Joined: Fri Apr 06, 2018 11:03 am

Re: Definition of moles

You are correct that moles are 6.022 x 10^23 amount of "things". However, I think you are getting confused over the meaning of a "mol of [element]". A mol of carbon and a mol of oxygen are different because we are comparing their masses. In this case, a mol of oxygen (16.00 g) has more mass than a mol of carbon (12.01 g), but the number of atoms we are comparing are the same.

005006577
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Re: Definition of moles  [ENDORSED]

An exact definition of moles is that a mole is a unit of measurement for the amount or sample of a chemical substance that contains as many constitutive particles as there are atoms in 12 grams of carbon-12, which can also be expressed by the Avogadro constant (6.022 x 10^23).

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