August 24, 2019, 02:15:36 PM
Forum Rules: Read This Before Posting


Topic: experiment: determine empirical formula  (Read 5330 times)

0 Members and 1 Guest are viewing this topic.

msandra

  • Guest
experiment: determine empirical formula
« on: July 25, 2004, 11:17:58 AM »
From the experiment, i used 0.490g metal (Mg) to combust with Oxygen to form a product 0.912g.

1. when i calculate the % oxygen,
0.422/0.912 x 100%=46.3% is that correct?

2. Then i caluclate the mole of oxygen
46.3g/16.00 = 2.89 mol
Should I use 16 or 32?

Offline jdurg

  • Banninator
  • Retired Staff
  • Sr. Member
  • *
  • Posts: 1366
  • Mole Snacks: +106/-23
  • Gender: Male
  • I am NOT a freak.
Re:experiment: determine empirical formula
« Reply #1 on: July 25, 2004, 01:14:35 PM »
I would assume that you would use 32 since the question is probably asking about how many moles of Oxygen gas are produced.  (However, you could stick with using 16 and just mention that you are reporting monatmoic Oxygen.  If you use 32, just be sure to report it as molecular oxygen gas so that if there are any questions the person going over your work will know what you were using).  
"A real fart is beefy, has a density greater than or equal to the air surrounding it, consists

ssssss

  • Guest
Re:experiment: determine empirical formula
« Reply #2 on: July 26, 2004, 04:39:42 AM »
From the experiment, i used 0.490g metal (Mg) to combust with Oxygen to form a product 0.912g.

1. when i calculate the % oxygen,
0.422/0.912 x 100%=46.3% is that correct?

2. Then i caluclate the mole of oxygen
46.3g/16.00 = 2.89 mol
Should I use 16 or 32?


In the first part you are calculating % of oxygen[ in atoms].So you are using its atomic mass,Whereas in second part where you are dealing with O2 in chemical reaction it means you are considering O2 molecule so you will use its molecular weight[ AND NOT ATOMIC WEIGHT] which is 32.You get it?
« Last Edit: July 26, 2004, 04:40:48 AM by ssssss »

Offline AWK

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 6531
  • Mole Snacks: +468/-79
  • Gender: Male
AWK

Sponsored Links