Coefficients and Subscripts

Jennifer Guzman 4C
Posts: 38
Joined: Wed Feb 14, 2018 3:01 am

Coefficients and Subscripts

Hi all! Can someone explain to me why we only multiply Stoichiometric coefficients and not also the subscript. Much appreciated, thanks!

Kristen Kim 2K
Posts: 70
Joined: Fri Sep 28, 2018 12:16 am

Re: Coefficients and Subscripts

The subscript indicates what kind of compound it is, so if the subscripts are changed, the actual compound would change as well. For example, if we want to indicate there are two molecules of formaldehyde, we would write 2(CH2O) instead of C6H12O6 (subscripts multiplied by 2), which would then indicate a molecule of glucose.

Tony Ong 3K
Posts: 63
Joined: Fri Sep 28, 2018 12:23 am

Re: Coefficients and Subscripts

Multiplying by the subscripts would change the chemical structure of the molecule and make an entirely different molecule. However when you multiply by the stoichiometric coefficients, you're essentially multiplying the subscripts as well because the stoichiometric coefficients apply to the entire molecule.
For instance, 4CO2 is equivalent to 4 moles of Carbon and 8 moles of Oxygen.
Last edited by Tony Ong 3K on Wed Oct 03, 2018 3:06 pm, edited 1 time in total.

Mikka Hoffman 1C
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am
Been upvoted: 2 times

Re: Coefficients and Subscripts

Hi! You don't multiply the subscript because it refers to how many atoms of that element are in the molecule not how many moles of the molecule are necessary in the equation. If you changed the subscript it would consequently change the molecular composition and the molecule would become a different molecule entirely.

Nicolle Fernandez 1E
Posts: 56
Joined: Fri Sep 28, 2018 12:25 am
Been upvoted: 1 time

Re: Coefficients and Subscripts

You don't multiply the subscripts because it will change the identity of the molecule for example if you have H2O and you multiply it by 2 you're supposed to have 2H2O which is 2 water molecules, but if you also multiply the subscripts you get 2H4O which is 2 molecules of hydrogen hydrate.