Talk:Empirical formula
From Wikipedia, the free encyclopedia
Can any body please solve this, show all the workings: 81.8 Carbon, 18.2 Hydrogen --Reeba 09:27, 19 July 2007 (UTC) 81.8*12=981.6/36.4=27 18.2*1=18.2*2=36.4/36.4=1 c=27 h=1
 |
This article is within the scope of WikiProject Chemistry, which collaborates on Chemistry and related subjects on Wikipedia. To participate, help improve this article or visit the project page for details on the project. | ||
|
Article Grading: The article has not been rated for quality and/or importance yet. Please rate the article and then leave comments here to explain the ratings and/or to identify the strengths and weaknesses of the article.. |
|||
 |
This article is within the scope of WikiProject Physics, which collaborates on articles related to physics. |
| ??? | This article has not yet received a rating on the assessment scale. [FAQ] |
| ??? | This article has not yet received an importance rating within physics. |
|
Help with this template Please rate this article, and then leave comments to explain the ratings and/or to identify its strengths and weaknesses. |
|
The definition given suggests that C3H7 is also a valid empirical formula for hexane, but I'm not sure if this is a flaw in the definition or not. Noser 19:29, 8 Dec 2004 (UTC)
- You are correct - it was a flaw in the example. Fixed it. -Vsmith 03:44, 10 Dec 2004 (UTC)
[edit] Valence exchange technique
I removed the following two paragraphs from the article.
- To calculate the empirical formula for two elements (excluding transition metals, lanthanides and actinides), switch the valency of the two elements involved. For example, equation for water is H2O. The valency of H (hydrogen) is 1, and the valency of O (oxygen) is 2. Switch the valencies and you get H2O.
- N.B. This only works for TWO elements.
The proposed calculation technique lists four exceptions: three large groups of elements, and any compound with more than two elements. But in this very article, the example of hexane contains only two elements, neither of which is in the listed exceptional groups, but hexane's empirical formula is C3H7, not CH4 as predicted by the technique
This makes me think that the technique is simply not worth the trouble. If any editor feels strongly about it, feel free to put it back, but please list all the exceptions (explaining why it fails for hexane, hydrazine, and hydrogen peroxide, for instance). Also include a reference to a reputable source which explains the technique and the reason it works. ACW 20:50, 11 June 2006 (UTC)
[edit] Chemical v Molecular v Empirical Formula
The article on Empirical Formula equates "chemical formula" with "empirical formula," and distinguishes "molecular formula"
The article on Chemical Formula equates "chemical formula" with "molecular formula" and distinguishes "empirical formula"
(There is no separate article on "Molecular Formula")
So who is right?
