Determining Formulas Based on Molecule

Moderators: Chem_Mod, Chem_Admin

paulacamara1E
Posts: 30
Joined: Fri Apr 06, 2018 11:05 am

Determining Formulas Based on Molecule

Postby paulacamara1E » Sun Apr 15, 2018 5:36 pm

When given a visual representation of a molecule it is possible to write both its empirical and molecular formulas, however, I am having a bit of confusion when it comes to doing so. Is it correct to count the number of elements for the molecular formula? What about the empirical formula?

Ignacio Ramirez 1J
Posts: 31
Joined: Tue Nov 14, 2017 3:02 am

Re: Determining Formulas Based on Molecule

Postby Ignacio Ramirez 1J » Sun Apr 15, 2018 5:51 pm

The definition of molecular formula is the actual formula of the molecule.Therefore, counting the number of each element should be fine if you are looking to find the molecular formula. The molecular formula has the smallest possible numbers that you are able to simplify. If you have C4H8O2, it can be simplified to C2H4O. C2H4O would be the molecular formula. If the visual representation provides an equation that can not be simplified, then that is the molecular formula.

Chem_Mod
Posts: 18193
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 429 times

Re: Determining Formulas Based on Molecule

Postby Chem_Mod » Sun Apr 15, 2018 6:26 pm

The molecular formula contains information how many atoms of each type a molecule possesses. So, when given a structure, you can simply count the number of atoms to get the molecular formula. The empirical formula represents the small possible ratio of atoms that a molecule has. So if the molecular formula is C4H8O2, then the empirical formula is C2H4O.

204917020
Posts: 31
Joined: Fri Apr 06, 2018 11:05 am

Re: Determining Formulas Based on Molecule

Postby 204917020 » Sun Apr 15, 2018 7:07 pm

For the molecular formula, you count the number of each element, for example 12 Hydrogen, 6 Carbon, and 6 Oxygen. so that would give a molecular formula of C6H12O6, then to find empirical you divide by the lowest common factor, in this case it's 6. so the empirical formula would be CH2O.

Amanda 1A
Posts: 31
Joined: Fri Apr 06, 2018 11:01 am

Re: Determining Formulas Based on Molecule

Postby Amanda 1A » Sun Apr 15, 2018 7:20 pm

Adding on to this! I'm not sure if it matters, but how do you arrange the elements in a chemical formula? As in, is there an order to put the elements in while answering a question where you're asked to write the molecular and empirical formulas?


Return to “Empirical & Molecular Formulas”

Who is online

Users browsing this forum: No registered users and 1 guest