Draw a dash and wedge representation of all the possible stereoisomers of 1,2- dichlorocyclopentane. Describe their relationship to one another and then describe their optical activity:

For which of the following molecules are there two unique configurations about the double bond? Explain. (a) (CH3)2C=CHCI; (b) H2C=CHCH,CH3; (c) CIHC=CHBr; (d) HC=CCH=CHCI

compare the bond lengths of the double and triple C-C bonds in C2H4 and C2H2. what impact does increasing the number of bonds have on the bond length?

Consider the skeletal structure of 1-Isopropyl-2-methylcyclohexane. Identify the number of hydrogen atoms bound to each carbon in the structure.

These molecules are called constitutional (or structural) isomers because they share the same chemical formula but have different patterns of atomic connectivity. Draw as many constitutional isomers as you can for C5H8 in bond-line notation. It may be helpful to draw a Lewis Structure for one of the isomers first.

The barrier to C-C bond rotation in bromoethane is 15 kJ/mol. What energy can you assign to an H-Br eclipsing interaction? Use strain energy increments from the table below in your calculation. Interaction (Specify units, kJ/mol; Calculate to nearest 0.1 energy units) H → H eclipsed H → CH3 eclipsed CH3 → CH3 eclipsed CH3 CH3 gauche Cause Torsional strain Mostly torsional strain Torsional and steric strain Steric strain (kJ/mol) Energy cost 4.0 6.0 11.0 3.8 (kcal/mol) 1.0 1.4 2.6 0.9