Jul 5, 2009
221
0
Status
Pre-Dental
kaplan workshops says.
'the unsaturated hydrocarbon tails are 'bent' and thus do not pack together as closely as saturated hydrocarbon tails'.....

I don't understand why because i think saturated carbons have all those C-H 'arms' around the carbon so they are harder to pack together..

anybody correct me?
 
May 28, 2009
130
0
Status
Pre-Dental
kaplan workshops says.
'the unsaturated hydrocarbon tails are 'bent' and thus do not pack together as closely as saturated hydrocarbon tails'.....

I don't understand why because i think saturated carbons have all those C-H 'arms' around the carbon so they are harder to pack together..

anybody correct me?

The saturation allows for the molecule to stack ontop of each other because it only contains a single bond between the H-C and the C-C, the single bond allows for stacking. The unsaturated has double bonds between the C=C and thus has a kink and cannot stack, therefore has a lower melting point and more fluidity.
 
Jun 14, 2009
800
3
Status
Pre-Dental
kaplan workshops says.
'the unsaturated hydrocarbon tails are 'bent' and thus do not pack together as closely as saturated hydrocarbon tails'.....

I don't understand why because i think saturated carbons have all those C-H 'arms' around the carbon so they are harder to pack together..

anybody correct me?
If you look at a space-filling model of a hydrocarbon, you can see that the C-H bonds don't do too much in terms of changing the shape of the chain. Unsaturated chains still have a C-H bond on each alkene carbon, as well. However, with an unsaturated point, the double bond kinks the entire rest of the chain at an odd angle.

Think about it. How well would you be able to fit in a crowded room if you were kicking your leg out everywhere?