1. Geometric Isomers  Lack of rotation around carbon-carbon double bonds has an important structural implication.

2.  These are not the same. Therefore, they cannot have the same name. cis-2-butene trans-2-butene  If the hydrogens are on the same side it is a cis configuration. If they are on opposite sides of the double bond it is a trans configuration.  These are not the same. Therefore, they cannot have the same name. cis-2-butene trans-2-butene  If the hydrogens are on the same side it is a cis configuration. If they are on opposite sides of the double bond it is a trans configuration.

3.  Name each: Cis-2-pentene 1-pentene Trans-2-pentene

4.  Name it:  C-C-C-C-C=C-C C H H 5-methyl-cis-2-heptene  Name it:  C-C-C-C-C=C-C C H H 5-methyl-cis-2-heptene

5. Stereoisomers  Molecules of the same molecular structure that differ only in the arrangement of atoms in space.  What does this mean?  You need to understand 2 terms:  1. Superimposable  Object is symmetrical - mirror image is no different then original.  Ex- ball  2. Nonsuperimposable  Mirror image cannot be placed on top of original  Ex- your hands  Molecules of the same molecular structure that differ only in the arrangement of atoms in space.  What does this mean?  You need to understand 2 terms:  1. Superimposable  Object is symmetrical - mirror image is no different then original.  Ex- ball  2. Nonsuperimposable  Mirror image cannot be placed on top of original  Ex- your hands

6. Stereoisomers  A chiral carbon is  asymmetrical when it has 4 different groups.  ex - CHFClBr  Where is the chiral carbon? C-C-C-C-C-C-C C C  A chiral carbon is  asymmetrical when it has 4 different groups.  ex - CHFClBr  Where is the chiral carbon? C-C-C-C-C-C-C C C