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Formula Units

Posted: Mon Sep 30, 2019 10:04 pm
by Robert Tran 1B
Is there a difference between atoms/molecules and formula units? Do formula units change when an ionic compound is dissolved?

Re: Formula Units

Posted: Mon Sep 30, 2019 10:14 pm
by Jack Riley 4f
"Formula Units" and "Molecules" are basically the same thing. The only difference is that formula units refer to ionic compounds while molecules refer to covalently bonded elements.

Re: Formula Units

Posted: Mon Sep 30, 2019 10:15 pm
by Kishan Shah 2G
I can give you a definitive answer to the first part of your question. Yes, formula units do mean the same thing as atoms. As for the second question, I would assume that formula units do not change for dissolved ionic compounds due to the fact that atoms are neither being created nor destroyed during this process. I could be wrong about this.

Re: Formula Units

Posted: Mon Sep 30, 2019 10:16 pm
by Chetas Holagunda 3H
In terms of the problems we are solving, I think they are the same since they are considered the same in the textbook questions. One mole is 6.022X10^23 of anything, so in order to calculate, just use Avogadro's number to solve for either atoms or formula units.

Re: Formula Units

Posted: Tue Oct 01, 2019 8:25 am
by britthanul234
Whenever a question asks you to find the formula units, it's simply asking you to find the number of atoms. So, if the question gives you the number of grams, divide it by the molar mass in order to figure out the number of moles. Then use Avogadro's number to find the number of atoms, which is the number of formula units.