JOHN Pros
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BOND STRUCTURE OF C3H6O3
How exactly do you know how to stretch out bonds and atoms in what spot? A good example would be C3H6O3.
How do we know that it needs a double bond with the Oxygen and why do we add the O to the H? These are the only things I can't understand in this
structure.
I am referring to this bond image: http://wakatipu.schoolzone.net.nz/Internet_Science/Chemistry...
Thank you very much
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BromicAcid
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With just the condensed formula like that you don't know where to put the bonds. You could have a number of isomers all with the same molecular
formula. There are however long-hand ways to write out the formula. Often you will see carboxylic acids written out as (-COOH) I have also seen (O)
used to denote a double bonded O such as -C(O)OH. Also more common at least for molecules of this size is to preserve that data by treating each part
separately, for example if this were dimethyl carbonate you would write it as CH3OC(O)OCH3. The point is C3H6O3 doesn't tell you the connectivity of
the atoms that make up the molecule.
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unionised
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Wiki lists a number of possible molecules of that formula
http://en.wikipedia.org/wiki/C3H6O3
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Nicodem
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Thread Moved
9-9-2012 at 06:57 |
woelen
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Another important thing is that atoms bond to each other, according to certain rules. E.g. a C-atom has 4 bonds, an O-atom has 2 bonds and a H-atom
has one bond. If e.g. an O-atom is connected to a C-atom through a single bond, then there MUST be another thing connected to the O-atom. If nothing
else is connected to the O-atom, then one knows that it is connected to the C-atom with 2 bonds and for the C-atom 4 - 2 = 2 bonds are left for
something else.
So, using these rules, a lot of structures can be ruled out, but with these rules, still many possibilities remain open, even for simple molecules
like C3H6O3.
A good exercise would be for you to draw all possible molecules for a simple formula. E.g. for C2H6O, there are two possible arrangements:
H3C-O-CH3 (dimethyl ether)
H3C-CH2-O-H (ethanol)
Both these structures satisfy the rules that C-atoms have 4 bonds, O-atoms have 2 bonds and H-atoms have 1 bond.
Try to do some exercises yourself, like drawing all possible structures for e.g.
C3H8O
C4H10
C4H8
Allow double bonds between atoms and closed structures.
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ChemistryGhost
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There are many possibilities. The molecule you're refering to is lactic acid. Like BromicAcid just said, carboxylic acids have the (-COOH) group.
Lactic acid is a carboxylic acid.
"Imagination is more important than knowledge" ~Einstein
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