Find Elements in Chemical Formulas - Get Names

[omni]

Is there a website where you can enter the Compound's chemical formula and it's will give us the names of elements?

like if i will enter to the website this chemical formula CH4 and it will give me the name Methane.


thanks.

 

[Filip Larsen]

Perhaps you can use WolframAlpha [1]. While it works when searching for "chemical compound CH4" and a few others I've tried, I have no idea how extensive their database is.

[1] http://www.wolframalpha.com/

 

[omni]

well thanks

 

[Borek]

While it is quite simple to name elements in the formula, it is in general not possible to name substance just from the formula. In the case of inorganic substances it is not that obvious, but in organic chemistry number of isomers grows pretty fast with number of atoms. Even something as simple as C₂H₆O is ambiguous.

 

[omni]

so how can i know for example what element there in this formula ch3ch2ch2ch2ch3?

what is the way to know it?
thanks.

 

[Borek]

First, you have to write it using proper capitalization.

Then you have to compare symbols with the list of symbols. In this particular case there are only two elements, C and H.

 

[omni]

ok and what mean the little number?

btw: this is real formula ch3ch2ch2ch2ch3

 

[pzona]

Well what do you know about organic chemistry? This is clearly an organic compound, and organic chains (hint) generally bond the way they're written. In CH3(CH2)3CH3 the two end carbons will be bonded to three hydrogens each. How do you think the other carbons will be bonded, based on this?

 

[Borek]

Question is now what omni knows about organic chemistry, question is what omni knows about formulas at all.

Omni: please use proper capitalization, ch₃ch₂ch₂ch₂ch₃ doesn't mean anything. If anything it should be written as CH₃CH₂CH₂CH₂CH₃.

Lower index means how many times atom (or group of atoms) is present in the molecule. Water molecule is H₂O - two atoms of hydrogen and one atom of oxygen. We omit ₁.

 

[omni]

oh ok so the little number mean how many atoms we got in the molecule ?

thnaks.

 

[Borek]

Close but not exactly. In your example - that's a kind of "semistructural formula" - it tels you how many atoms of hydrogen are attached to particular carbon atom.

Note that semistructural formulas are not codified, that is, there is no set of rules that tells how to write them and what do they mean. In most cases that's not a problem, but sometimes they can be confusing and their use differs from lab to lab and from book to book.