Formula Units

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JOtomo1F
Posts: 66
Joined: Sat Aug 24, 2019 12:16 am

Formula Units

Postby JOtomo1F » Tue Oct 08, 2019 5:31 pm

Can someone explain what formula units are? I am a bit unclear about this topic.

A Raab 1K
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Joined: Sat Aug 24, 2019 12:16 am

Re: Formula Units

Postby A Raab 1K » Tue Oct 08, 2019 5:40 pm

A formula unit can be an atom, compound, or molecule. For example, if a question asks how many formula units of H2O are in one mole of H2O, then you would just find the number of atoms in one mole of H2O.

kim 2I
Posts: 105
Joined: Thu Jul 25, 2019 12:17 am

Re: Formula Units

Postby kim 2I » Tue Oct 08, 2019 5:42 pm

From what I know, formula units can be interchangably used with the number of molecules or atoms, so using Avogadro's number should work for any question asking for a compound's formula units. Something to keep in mind is that formula units usually refer to ionic compounds while molecules refer to molecular compounds.

Kylie Lim 4G
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Joined: Sat Aug 17, 2019 12:15 am

Re: Formula Units

Postby Kylie Lim 4G » Tue Oct 08, 2019 5:45 pm

A formula unit is the same as the empirical formula for an ionic compound (composed of cations and anions). They are written as formula units because they don't normally exist as individual molecules.

Minh Ngo 4G
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Joined: Thu Jul 25, 2019 12:17 am

Re: Formula Units

Postby Minh Ngo 4G » Tue Oct 08, 2019 6:41 pm

I think of it as the unit for compound.

Kelsey Ash 1D
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Joined: Wed Sep 18, 2019 12:16 am

Re: Formula Units

Postby Kelsey Ash 1D » Tue Oct 08, 2019 11:29 pm

Formula units can be an atom, compound, or a molecule. So basically you just have to use Avogadro's number to solve the equation.

Abigail Menchaca_1H
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Joined: Sat Sep 07, 2019 12:19 am

Re: Formula Units

Postby Abigail Menchaca_1H » Tue Oct 08, 2019 11:36 pm

It's used for conversion to atoms, compounds, and molecules.

Emily Vainberg 1D
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Joined: Sat Jul 20, 2019 12:15 am

Re: Formula Units

Postby Emily Vainberg 1D » Thu Oct 10, 2019 11:16 am

I had this question too, since the book used it in a confusing way. I asked my TA and he said that formula units is the empirical formula but for an ionic compound. However, since we don't need to know what an ionic compound is yet, when they ask for formula units they just means molecules.

JOtomo1F
Posts: 66
Joined: Sat Aug 24, 2019 12:16 am

Re: Formula Units

Postby JOtomo1F » Thu Oct 10, 2019 9:20 pm

Emily Vainberg 1L wrote:I had this question too, since the book used it in a confusing way. I asked my TA and he said that formula units is the empirical formula but for an ionic compound. However, since we don't need to know what an ionic compound is yet, when they ask for formula units they just means molecules.


Yeah, I was reading through the textbook and got confused when it was brought up. Thanks for the explanation!

salvadorramos3k
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Joined: Wed Sep 18, 2019 12:18 am

Re: Formula Units

Postby salvadorramos3k » Fri Oct 11, 2019 12:35 am

Formula units are basically the amount/number of something in a given bit of information. Formula units can be atoms or molecules. Basically, to find them you just need to multiple by Avogadro's number.

Brynne Burrows 3K
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Joined: Thu Jul 25, 2019 12:16 am

Re: Formula Units

Postby Brynne Burrows 3K » Fri Oct 11, 2019 1:12 am

Formula units are the amount of said material object, such as molecule, atom, compound, etc. The formula units are a quantitative measurement of the amount of any given thing.


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