Naming Compounds (F13)

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Haley Dveirin 1E
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Naming Compounds (F13)

Postby Haley Dveirin 1E » Tue Oct 01, 2019 8:30 pm

In problem F13 it asks you to name the compound PCL^5 (5 is a subscript) and the answer is Phosphorus Pentacholide. How do you know its chloride as opposed to chlorine/are there any other name-related things we should know?

Minh Ngo 4G
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Re: Naming Compounds (F13)

Postby Minh Ngo 4G » Tue Oct 01, 2019 8:48 pm

I think when naming covalent compounds, the ending always end with -ide.

Jorja De Jesus 2C
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Re: Naming Compounds (F13)

Postby Jorja De Jesus 2C » Tue Oct 01, 2019 9:03 pm

From what I remember from high school, there is a system for naming chemical compounds. I don't remember it completely but I think the naming has to do with which atoms or molecules are the positive ions and which are negative ions. The positive ions keep their names like Na or sodium. Negative ions' names change and the suffix -ide is added. Chlorine is a negative ion so the name becomes chloride. There are also a bunch of other factors involved in the naming process such as whether or not the compound is polyatomic (which put the names of the compounds first like ammonium instead of the elements), whether it the elements are metals or not (which will give the name a Roman numeral), whether it is an acid or base (for example if it is an acid the suffix will become -ic), and so much more. It is a lot to take in, but I hope I helped out for now. If you want to dive further into it, here a website that I think explains nomenclature better than I do: http://chemed.chem.purdue.edu/genchem/t ... names.html

Ying Yan 1F
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Re: Naming Compounds (F13)

Postby Ying Yan 1F » Tue Oct 01, 2019 9:06 pm

The Chlorine is actually already a compoud itself with the name Cl2, while chloride is the actual element Cl. So from how I interpret it, I think you would use chloride instead of chlorine in that problem is because the compoud is PCl5. Since the subscript on Cl is 5, we could eliminate chlorine as the name because it's not Cl2. Hope that helps!

AnnikaMittelhauser4E
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Re: Naming Compounds (F13)

Postby AnnikaMittelhauser4E » Tue Oct 01, 2019 9:29 pm

In both ionic and molecular compounds, the ending of the second element is changed to -ide. In ionic compounds, the second element is the one that acts as an anion. Generally in molecular compounds, the element further to the right on the periodic table is the second one. So, in this case, chlorine is farther right than phosphorous so it takes the -ide ending.
Other naming stuff to be aware of...
- In ionic compounds, you have to specify the charge of the cation transition metals b/c their charges can vary. You can figure out the charge by seeing what cancels out the anion. An example of a none transition metal compound is NaCl (sodium chloride) and a transition metal one is FeCl2 (Iron (II) Chloride) or Fe2O3 (Iron (III) Oxide).
- In molecular compounds you add prefixes to indicate how many of each element there is. You can skip the prefix if there is only one of the element and it is the first one named.

The Fundamentals D section of the textbook goes into more details :)

Maya Beal Dis 1D
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Re: Naming Compounds (F13)

Postby Maya Beal Dis 1D » Wed Oct 02, 2019 2:27 pm

How many of the naming rules do we need to know for the test next week? Do we need to have the names and charges of polyatomic ions memorized or will they be given if needed to solve a problem?

Megan Cao 1I
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Re: Naming Compounds (F13)

Postby Megan Cao 1I » Wed Oct 02, 2019 3:03 pm

whenever you're naming chemical compounds, they'll usually end in -ide. -ine is just for name of the element

Megan Cao 1I
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Re: Naming Compounds (F13)

Postby Megan Cao 1I » Wed Oct 02, 2019 3:08 pm

Maya Beal Dis 1E wrote:How many of the naming rules do we need to know for the test next week? Do we need to have the names and charges of polyatomic ions memorized or will they be given if needed to solve a problem?


I don't think we'll be tested on the naming rules, but you may need to know them so that you can identify the compounds on the test, if they aren't given already. I think you should know the more basic polyatomic ions such as ammonia or phosphate (-3) /sulfate (-2) /nitrate (-1). For the most part I think he'd give the general information needed to solve the problem.


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