Isomers and polymers

Structural Isomers Pentane and 2-methylbutane are both C5H12. 1-butene 2-methylpropene cyclobutane methylcyclopropane C4H10 has 2 isomers (2-methylpropane, butane). C4H8 has more isomers because the position of the double affects the name and because ring structures can be drawn.

Geometric Isomers cis = same side, trans = opposite sides 1,2-dichloroethene requires cis or trans. 1,2-dichloroethane does not require cis or trans because they would both represent the same molecule (to move chlorine from the same side to opposite sides only requires that the C – C single bond be rotated). cis-1,2-dimethylcyclopentane trans-1,2-dimethylcyclopentane

1,1-dimethylcyclopentane A molecule is relatively inflexible when a multiple (double or triple) bond is present or if a ring structure (including benzene) exists. a) not isomers (they don’t have the same chemical formula: C5H12 vs. C5H10) b) structural isomers (same as question #1) c) geometric isomers d) not isomers (both diagrams represent the exact same molecule)

Polymers Monomer: the smallest repeating unit of a polymer (propene in polypropylene). Polymer: a long chain molecule made up of many small identical units (monomers). Addition polymerization: a reaction in which unsaturated monomers combine with each other to form a polymer. Teflon, polypropylene, polyester, polyethylene (pop bottles, grocery bags), polystyrene (packing material), Plexiglas, polyvinyl chloride (vinyl), natural rubber, etc.

Geometric Isomers cis-1,2-dichloroethene trans-1,2-dichloroethene cis-1,2-dichlorocyclopentane trans-1,2-dichlorocyclopentane cis-1,2-dichloroethene trans-1,2-dichloroethene For more lessons, visit www.chalkbored.com