Avogadro's Number

[Brendan Duong 1I]

Can someone explain to me when we would multiply a unit by avogadros number and when we would divide by avogadros number

[Jaden Ji 2K]

We would multiply a unit by Avogadro's number if the weight, energy, etc. of a single atom were given and you wanted to find the weight, energy, etc. in mols. To find the weight, energy of a single atom you would divide the number of mols by Avogadro's number in order to figure out how much each atom has.

[Aaron Akhavan-Dis1B]

We use Avogadro's number when converting from moles to atoms/molecules or vice versa. Depending on how you do your dimensional analysis, you can either divide or multiply by Avogadros number which has a unit of atoms/molecules.

[Taylor K 2D]

When going from moles to atoms/molecules, you would divide by Avogadro’s number, and when going from atoms/molecules to moles, you would multiply by Avogadro’s number.

[Silvi_Lybbert_3A]

Just as a note for the final, I've noticed we've had to use Avogadro's number a lot during questions about the photoelectric effect. For example, if the question says the energy needed to remove an electron is 490 kJ/mol, you have to concert this into J/photon using Avogadros's number.
So, I'd say be extra careful with units and Avogadro's number with photoelectric questions! Of course be careful of units always though:)

[505612629]

divide by Avogadro's # when going from moles -> atoms/molecules
multiply by Avogadro's # when going from atoms/molecules -> moles

[Dane_Beasley_1E]

You would divide by Avogadro's number when converting from moles to atoms/molecule, and you would multiply by Avogadro's number when converting from atoms/molecule to moles.

[George Hernandez 3I]

I could be wrong but shouldn't you multiply by Avogadro's number if you're trying to go from moles to molecules/atoms (i.e. 5 moles of carbon * 6.022*10^23 = number of atoms of carbon).

[AlbertGu_2C]

In a more general sense, Avogadro's number is just the amount of objects in one mole. So if you were to set up a dimensional analysis table to solve a question, you should be using Avogadro's number as (6.0221*10^23)objects/mole

[Morgan Gee 3B]

Avogadro's number is used to describe the quantity of some object in one mol. As a result, you use Avogadro's number during some form of dimensional analysis relating to a mol. As for when you would divide or multiply by Avogadro's number, that can be determined by looking at the units of the previous value. For example, 1.008 g/mol has mol on the bottom so you would divide by Avogadro's number to find the mass of each hydrogen atom.

[Bai Rong Lin 2K]

You would apply it when going from moles to molecules or atoms.

[Adam_ElSayed_3B]

The roadmap we've seen in stereochemistry explains the use of Avogadro's number. From going from moles to atoms or vice versa, Avogadro's number is the way to go.

[205323697]

What will be asked in a problem in order to know that we have to use this constant?