Question

Laboratory Work

1.   Draw the skeletal formulas and make models of the three constitutional isomers of C5H12.

2.   Draw Kekule structures and make models of all the constitutional isomers of C2H4Cl2.

3.   Draw Kekule formulas and make models of ethane, ethene, and ethyne. How does the geometry of their structures differ? Which compound contains sp hybridized carbons?                                                                                                                      

4.   Draw and label the Newman projection and make the model of the anti-conformation of 1,2-dibromoethane. Rotate around the carbon-carbon bond 360⁰ and identify and draw the two gauche conformations. Draw these. Draw and identify the conformation with the highest energy.

5.   Write the Kekule formulas and make models of cyclopropane and cyclopentane. Do not use the flexible bonds for these structures. Why is cyclopentane less strained than cyclopropane?

6.   Write skeletal formulas and make models of the various C4H9Cl isomers. Recognize visually the difference between n-butyl chloride, sec-butyl chloride, iso-butyl chloride and tert-butyl chloride. Which of these isomers are primary alkyl halides?

7.   Write skeletal formulas and make models of the chair and boat conformations of cyclohexane. Why is the chair conformation more stable (less potential energy) than the boat conformation?

8. Write skeletal formulas and make models for cis-1,4-dimethylcyclohexane and trans-1,4-dimethylcyclohexane. Be clear about axial and equatorial in your skeletal drawing. Carefully twist your models to simulate ring flips. Are there two possible chair conformations of trans-1,4-dimethylcyclohexane? Are there two possible chair conformations of cis-1,4-dimethylcyclohexane?

9. Draw and make models of the cis and trans isomers of 1,3-dimethylcyclohexane and evaluate the two possible chair conformations of each model for relative stabilities.

Answer 1