Fundamentals E25

[Nick Fiorentino 1E]

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]

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).

[AGulati_4A]

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]

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]

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]

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.