21 April 2011

opps sorry!

After some research, I know realise that I got one of my facts wrong during my talk in Sweden.

The premise I stated was that water molecules are bigger than alcohol molecules when the reverse is actually true and alcohol molecules are actually much bigger than water.

However the principle still stands of why alcohol has a lower boiling point than water because boiling point is not an indication of size but rather of how strong are the forces holding one molecule to the next. In the case of water the forces are very strong - they are called hydrogen bonds - and there is a multiple cross - linking between molecules. So each water molecule is strongly connected to at least four others. In ethanol the presence of CH2CH3 group reduces the ability to crosslink.

The points I made are still relevant as that is how it reacts. However I did get the size wrong!

Tony C

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