Chemical unit vs. Formula unit

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DHavo_1E
Posts: 96
Joined: Sat Aug 17, 2019 12:17 am

Chemical unit vs. Formula unit

Postby DHavo_1E » Tue Oct 01, 2019 6:20 pm

Hello,

I am confused about the difference between a chemical and formula unit. Please provide insight on what they mean in chemistry and problem solving. Thank you!

Jacey Yang 1F
Posts: 86
Joined: Fri Aug 09, 2019 12:17 am

Re: Chemical unit vs. Formula unit

Postby Jacey Yang 1F » Tue Oct 01, 2019 7:03 pm

The formula unit is the lowest whole number ratio of ions in an ionic compound. It's basically the empirical formula for an ionic compound. As for chemical unit, I've never heard of that before and I don't think it exists. Perhaps you mean chemistry units, which are just units of measurement?

Jada Brown 2H
Posts: 91
Joined: Sat Aug 17, 2019 12:15 am

Re: Chemical unit vs. Formula unit

Postby Jada Brown 2H » Tue Oct 01, 2019 8:28 pm

Another way to think about the formula unit is just as the single, smallest unit of whatever you are dealing with. It is similar to the concept of a single atom or a single molecule.

Maeve Miller 1A
Posts: 51
Joined: Fri Aug 09, 2019 12:16 am

Re: Chemical unit vs. Formula unit

Postby Maeve Miller 1A » Wed Oct 02, 2019 7:15 pm

Usually in the homework when it asks you to convert to formula units, it requires you to multiply by Avogadro's constant (6.022 * 10^23) in order to get molecules. I found this to be the case for the assigned problems in the E section of fundamentals.

MMckinney_4H
Posts: 61
Joined: Sat Sep 28, 2019 12:16 am

Re: Chemical unit vs. Formula unit

Postby MMckinney_4H » Wed Oct 02, 2019 8:41 pm

I'm not entirely sure what you are referring to with the term "chemical unit" but if you mean "molecular formula," then the difference between a formula unit (the empirical formula) and the molecular formula would be that the empirical formula is the ratio between the atoms in a compound while the molecular formula specifies how many of each atom there is. Take glucose for example. It's empirical formula, or the formula for any carbohydrate is CH₂O. However its molecular formula is C₆H₁₂O.

Aliya Roserie 4F
Posts: 5
Joined: Fri Aug 09, 2019 12:16 am

Re: Chemical unit vs. Formula unit

Postby Aliya Roserie 4F » Wed Oct 02, 2019 9:35 pm

DHavo_3H wrote:Hello,

I am confused about the difference between a chemical and formula unit. Please provide insight on what they mean in chemistry and problem solving. Thank you!



I also have a question in regards to using Avogadros"s number. Is there a certain formula to use when trying to work with conversions with atoms? Can someone give an example?

DHavo_1E
Posts: 96
Joined: Sat Aug 17, 2019 12:17 am

Re: Chemical unit vs. Formula unit

Postby DHavo_1E » Sat Oct 05, 2019 9:37 pm

Aliya Roserie 4F wrote:
DHavo_3H wrote:Hello,

I am confused about the difference between a chemical and formula unit. Please provide insight on what they mean in chemistry and problem solving. Thank you!



I also have a question in regards to using Avogadros"s number. Is there a certain formula to use when trying to work with conversions with atoms? Can someone give an example?



Hi,

1 mol = 6.022 x 10^23 objects (could be molecules or formula units) An example could be if a question asked you to convert the amount of formula units from 0.521g of NaCl. First, you would convert 0.521g NaCl x ( 1mol NaCl/ 58.44g NaCl) = 0.00891513 mol NaCl. Then, you would multiple 0.00891513 mol NaCl x (6.022 x 10^23 formula units/1 mol) to get 5.37 x 10^21 formula units of NaCl.


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