## Fundamentals E25

Nick Fiorentino 1E
Posts: 102
Joined: Wed Sep 18, 2019 12:16 am

### Fundamentals E25

On question E25 part a, it asks for the formula units in .750mol KNO3. What are formula units and how would I calculate them?

Haley Chun 4H
Posts: 54
Joined: Sat Aug 17, 2019 12:18 am

### Re: Fundamentals E25

In this question, I think formula units basically means the number of molecules (which you can find by multiplying the number of moles of KNO3 given by Avogadro's number).
Last edited by Haley Chun 4H on Thu Oct 03, 2019 3:18 pm, edited 1 time in total.

AGulati_4A
Posts: 74
Joined: Sat Sep 07, 2019 12:19 am

### Re: Fundamentals E25

Formula units is the number of atoms in in a certain quantity of a compound. In this case, you would simply need to cover .750 mol into number of atoms thus multiplying it by (6.023 x 10^23 atoms/mol) -- or Avogadro's constant

AGulati_4A
Posts: 74
Joined: Sat Sep 07, 2019 12:19 am

### Re: Fundamentals E25

Haley Chun 4H wrote: Avogadro's number. Sorry to be so technical, but this number would be considered Avogadro's constant as you are using (6.023 x 10^23 atoms/ mol) not just atoms).

philipraj_1F
Posts: 52
Joined: Fri Aug 30, 2019 12:16 am

### Re: Fundamentals E25

I think formula units is a name for units in an ionic compound, while atoms refers to that of an element by itself, and molecules refers to that of a covalent compound. You would multiply it by avogadro's number the same way with anything else. So it would be .750 mol KNO3 x (6.022x10^23 formula units/ 1 mol KNO3).

Verity Lai 2K
Posts: 100
Joined: Sat Aug 24, 2019 12:18 am

### Re: Fundamentals E25

Formula units is used for ionic compounds, but it uses the same avagadro's number as if you were finding the number of atoms. When a problem asks for the formula units, it is essentially asking for the number of atoms.