Chemical Forums

Please login or register.

Login with username, password and session length

Sponsored links

Pages: [1]   Go Down

Author Topic: How to calculate the mole of an element in a compound?  (Read 487 times)

0 Members and 1 Guest are viewing this topic.

Kommandante

  • New Member
  • **
  • Mole Snacks: +0/-0
  • Offline Offline
  • Posts: 3
How to calculate the mole of an element in a compound?
« on: December 09, 2013, 10:44:38 AM »

Hi there,

I have been given the formula for Iron(III) Oxide (Fe2O3) and have been asked to calculate how many moles are present in 24.6g of the compound whilst working out how many moles of Fe are present in this amount.

I have calculated the mole of Fe2O3 at 0.154 mol,
M= (Fe2O3), M= 2(55.8 ) + 3(16.0)
m = 24.6, M = 159.6, n = ?   so, n = m/M, 24.6/159.6 = 0.154mol

I cannot for the life of me grasp how to find out the mol of Fe in 24.6g this compound.
Do I divide the mol of Iron by the weight of the compound? Convert it to a percentage?

Any help would be greatly appreciated
Logged

Hunter2

  • Sr. Member
  • *****
  • Mole Snacks: +91/-28
  • Offline Offline
  • Gender: Male
  • Posts: 1119
  • Vena Lausa moris pax drux bis totis
Re: How to calculate the mole of an element in a compound?
« Reply #1 on: December 09, 2013, 07:01:47 PM »

its more easier.  You know the moles of the compound then you know also the moles of each atom. Its given to the formula. Example 1 mol NaCl  contain also 1 mol Na+ and 1 mol Cl-. So how much is it for the iron oxide.
Logged

Kommandante

  • New Member
  • **
  • Mole Snacks: +0/-0
  • Offline Offline
  • Posts: 3
Re: How to calculate the mole of an element in a compound?
« Reply #2 on: December 09, 2013, 07:57:09 PM »

Since the compound is 0.154 mol, does that mean there are 2(0.154)mol Fe?
Logged

Hunter2

  • Sr. Member
  • *****
  • Mole Snacks: +91/-28
  • Offline Offline
  • Gender: Male
  • Posts: 1119
  • Vena Lausa moris pax drux bis totis
Re: How to calculate the mole of an element in a compound?
« Reply #3 on: December 09, 2013, 08:19:06 PM »

Exactly. correct.
Logged

Kommandante

  • New Member
  • **
  • Mole Snacks: +0/-0
  • Offline Offline
  • Posts: 3
Re: How to calculate the mole of an element in a compound?
« Reply #4 on: December 09, 2013, 08:53:58 PM »

Thanks for your help,
Greatly appreciated!
Logged
Pages: [1]   Go Up
 

Mitch Andre Garcia's Chemical Forums 2003-Present.

Page created in 0.081 seconds with 23 queries.