Chemical formula?

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Nahal 1F
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Joined: Fri Jun 23, 2017 11:39 am

Chemical formula?

Postby Nahal 1F » Sun Jul 16, 2017 6:24 pm

How do you find the chemical formula of compounds?

For example, chronium(III) and manganese(II)

Timothy Kao 1B
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Joined: Fri Jun 23, 2017 11:39 am

Re: Chemical formula?

Postby Timothy Kao 1B » Sun Jul 16, 2017 7:44 pm

Section D in fundamentals goes over how to derive the chemical formula from a compound's name.

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Joined: Fri Sep 29, 2017 7:07 am

Re: Chemical formula?

Postby mayapartha_1D » Sun Oct 22, 2017 4:54 pm


You usually will not have to find a chemical formula without any given values. Metals, gases, etc. have different characteristics that make them easier to figure out; which is listed in the book.

Hope this helped.

Katie Lam 1B
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Joined: Fri Sep 29, 2017 7:06 am

Re: Chemical formula?

Postby Katie Lam 1B » Sun Oct 22, 2017 7:28 pm

The Roman numerals refer to the charge on that atom. In this case, chromium has a +3 charge so you know how to write the formula for a neutral molecule.

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Joined: Thu Jul 27, 2017 3:00 am

Re: Chemical formula?

Postby Kyung_Jin_Kim_1H » Sun Oct 22, 2017 10:55 pm

Hi! In addition to what others have mentioned above, it's helpful to know the charges of the common elements on the table. For example, Group I all has a +1 charge, Group II has +2, etc. Once you know the charges of the elements in your compound, you can find out how many atoms of an element are in it. (Ex. Copper (II) Chloride --> Copper has +2 charge, chloride has -1 charge, the molecule has a net charge of 0, so there must be 2 chlorides --> CuCl2 ).

Jean Mok 3K
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Joined: Sat Jul 22, 2017 3:01 am

Re: Chemical formula?

Postby Jean Mok 3K » Fri Oct 27, 2017 1:41 am

The chemical formula of compounds can be created using rules that can be generalized used on patterns. These rules can be found in the fundamentals part of the textbook (section D). The two things you ask of, however, are cations and perhaps you mean to ask how to find the charges for them. For transition metals, the roman numeral will be the charge. Hope this helps!

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