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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: linny on June 10, 2009, 08:54:52 am

Title: polysaccharides
Post by: linny on June 10, 2009, 08:54:52 am

"what is the molecular formula of the polysaccharide containing 5 ether linkages, and which is formed from the condensation of glucose molecules?"

question from tsfx revision notes; after looking at the answers for it; i dont think i would get anywhere near the answer; what would your processes of thinking be??

Title: Re: polysaccharides
Post by: shinny on June 10, 2009, 11:01:30 am

Ok, so first, break up what we know.
1. We've got 5 ether linkages
2. These ether linkages result from the condensation of glucose molecules
3. It's a polysaccharide

Hence,
From 1 we get; 5 bonds in between glucose molecules means that there are SIX glucose molecules. Draw it on paper if you don't get this.
From 2 we get; Since it's stated that these ether (glycosidic) linkages are formed from condensation, we know that each bond results in the release of a molecule of WATER. Therefore, if you've got 5 ether bonds, you're releasing 5 molecules of water as each one results in the release of one molecule of water.

Hence, we have:
Molecular formula=
=
=