2. two isomers for 2-butene
• Cis-: “on the near side of”
• Trans-: “across, beyond, transverse”
• These are almost the same the only difference is
whether the fourth carbon added goes on the
same side as the third or not.
• Chemical formula is C4H8
• Average molar mass 56.11 g/mol
5. Extra Fact
• This is the most simple alkene
showing cis/trans isomerism,
meaning it exists as two geometric
isomers.
• They are very difficult to separate by
distillation due to their close boiling
points
6. Summary
• Double bonds can not rotate due to the strength
of their bonds, but single bonds can because they
have less connection.
• Even though these two isomers have the same
formula they are very different structures with
different names.
