Nomenclature

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GFolk_1D
Posts: 91
Joined: Fri Aug 09, 2019 12:15 am

Nomenclature

Postby GFolk_1D » Sat Sep 28, 2019 11:25 am

Hi! I wasn't sure which topic to place this under and figured this was closest to general chemistry basics.... does anyone have any tips on help with nomenclature? I do not have a strong background in chemistry and am looking for some help with understanding the compound names etc. Thanks!

CalvinTNguyen2D
Posts: 87
Joined: Thu Jul 25, 2019 12:16 am

Re: Nomenclature

Postby CalvinTNguyen2D » Sat Sep 28, 2019 1:39 pm

Hey there! Nomenclature is a bit hard to get going at first, but once you get the hang of it it's a lot more straightforward!

The first thing to do is to identify whether a compound is ionic or molecular- ionic compounds will have a metal element in them, while molecular compounds will have non-metals.
The second element in every compound will usually have a -ide suffix (Oxide, Fluoride, Sulfide, etc.)

In an ionic compound, if the metal element is a transition metal, then you will need to add in a Roman Numeral indicating its charge. For example, Cu(II)O is Copper(II) Oxide, with the Copper atom having a charge of +2 to balance Oxygen's -2.

If the compound is molecular, then the elements will usually have a suffix in front of it that corresponds to its quantity within the compound. For example, S2Cl2 is Disulfur Dichloride. If the first element has only one atom, then there's no need to put any suffix (e.g. SO2: Sulfur Dioxide).

This is a very helpful link to get a better understanding! Hope this helped you!
https://medium.com/countdown-education/ ... 25ed57bd13

Alexa Mugol 3I
Posts: 54
Joined: Sat Aug 17, 2019 12:17 am

Re: Nomenclature

Postby Alexa Mugol 3I » Sat Sep 28, 2019 9:58 pm

Additionally, if there is an ionic compound with a polyatomic ion in it, you would have to use the name of the polyatomic ion (it's usually the anion).
For example: NaOH = sodium hydroxide, CaCO3 = calcium carbonate, Cu(NO3)2 = copper(II) nitrate, (NH4)2S = ammonium sulfide

Hope this helped :)

Amy Pham 1D
Posts: 88
Joined: Fri Aug 09, 2019 12:15 am

Re: Nomenclature

Postby Amy Pham 1D » Sun Sep 29, 2019 12:31 pm

Just to clarify, in the naming of cations, there are two possibilities:
a) if there's only one charge option, e.g. Na+, Ca^2+, Al^3+... just write "'element name' ion"
b) if there are multiple charge options, e.g. Cu+: copper(I), Cu^2+: copper (II), Fe^2+:iron(II)

In naming anions, change the end of the element name to "-ide."
e.g. O2 "oxygen, O^2- "oxide."

And just for more practical tips, writing flash cards to memorize common ions really helped me get the hang of nomenclature! One side for the chemical formula and one side with the written out name. Hope this helps!

Sean Cheah 1E
Posts: 87
Joined: Wed Sep 18, 2019 12:20 am

Re: Nomenclature

Postby Sean Cheah 1E » Mon Sep 30, 2019 7:23 pm

For ionic compounds, I'd highly recommend that you take a look at a table of common ions and make a serious effort to memorize both their names and charges (using flashcards or whatever method works best for you). Learning the names (paying special attention to those pesky prefixes and suffixes) lets you easily derive a chemical name from a molecular formula. Learning the various charges lets you write the correct molecular formula by simply balancing the charges of the ions that appear in the chemical name.

For covalent compounds, it would be a great idea to familiarize yourself with all the Greek counting prefixes (mono-, di-, tri-, etc.) as they are often used to denote the number of atoms of each element that are present in one molecule of the given compound (think carbon dioxide).

If necessary, I can make a separate post on the basics of organic nomenclature but I'd really prefer not to.


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