Jump to content

# Help with moles?

## Recommended Posts

I was wondering if someone knows any source thats really good at explaining moles. Also if you know how to answer this question please explain how: 5.60 x 10^25 atoms of H = _______ mol of H2O.

#### Share this post

##### Share on other sites

The individual terms should be fairly intuitive to see. For example the last term is just from definition of Avogadro's number and definition of mol. The hard part is knowing whether you multiply them or divide. So you want mol of water as the final "unit" so you want all the intermediate "units", such as H nuclei, water molecules all to cancel out.

@Msj ChemYou are absolutely right! Thank you for pointing that out.

Edited by kw0573

#### Share this post

##### Share on other sites

You could try my video on moles:

• 1

#### Share this post

##### Share on other sites
On March 19, 2016 at 4:44 AM, MariamXO said:

I was wondering if someone knows any source thats really good at explaining moles. Also if you know how to answer this question please explain how: 5.60 x 10^25 atoms of H = _______ mol of H2O.

One water molecule is made of 1 O atom and 2 H atoms. If you have 5.60 x 10^25 H atoms, you would have 5.60 x 10^25 / 2 = 2.8 x 10^25 water molecules. One mole of water contains 6.02 x 10^23 water molecules. Now you can calculate mol of H2O.

#### Share this post

##### Share on other sites
On March 19, 2016 at 5:13 AM, kw0573 said:

The individual terms should be fairly intuitive to see. For example the last term is just from definition of Avogadro's number and definition of mol. The hard part is knowing whether you multiply them or divide. So you want mol of water as the final "unit" so you want all the intermediate "units", such as H nuclei, water molecules all to cancel out.

One mole equals 6.02 x 10^23, not x 10 ^26. The answer should be 46.5 mol

• 1

## Create an account or sign in to comment

You need to be a member in order to leave a comment

## Create an account

Sign up for a new account in our community. It's easy!

Register a new account

## Sign in

Already have an account? Sign in here.

Sign In Now

×

## Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.