tommykins
i am number -e^i*pi
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- Feb 18, 2007
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- HSC
- 2008
回复: Re: Chemistry Question HSC 2007
you seem very informed in it, good luck mate.minijumbuk said:Condensation polymer is a polymer created by removing a H2O molecule to join two monomers, eg. Cellulose is a condensation polymer of glucose.
CH2CH2 is the 'condensed structural formula' for ethene. It's just a lazy way to make structural formulas. Like say 1-propanol. The condensed structural formula would be CH3CH2CH2OH. Although this looks like the 2nd C is joined to the first 3 H, it's not the case. That's the point of the condensed structural formula. It basically breaks up each molecule into several smaller bits.
The molecular formula of propanol could be C3H8O.
The full structural formula would be...
H H H
:mx:| | |
H-C-C-C-O-H
| | |
H H H
I hope that tells you enough about what the difference between each is.
Now, to answer you question about the bromine reaction:
They rarely ask you to draw condensed structural formula for reactions. Mostly, it'd be molecular or structural. In that case, just add up all the number of atoms in the reactants/products if they ask for a molecular formula. If not, then you must draw all the bonds in the correct order, with the atoms in the appropriate positions.
Also: Although they usually say "bromine water", which is technically HOBr, they actually mean Br2, though I guess either would be marked as correct. I just find it less troublesome to use Br2 instead. Just break up the double bond and put 2 new Br atoms on each C atom. Easy work xD
And I'd kill myself if I didn't get a band 6 in chemistry =P It's my best subject xD