In Chapter 8, we study the chemistry of alkenes, like ethene. In contrast to ethane, there is no free rotation around the C = C double bond of ethene. Explain this in the context of the molecular orbital picture of ethene.

Using the Newman projections shown, draw each molecule in its line-angle drawing with all hydrogens and substituents shown. [Carbon b is behind carbon a in these structures.] Wedges and dashes should be used to indicate whether a substituent is coming out of, or going into, the plane of the page.

(d)

For each molecule, draw the Newman projection you would observe if you looked down the C_a - C_b bond in the direction indicated.

(d) <IMAGE>

When we begin studying reactive intermediates, the designation of substitution will be especially important. Label the following carbocations as 1° , 2°, 3°, or 4° or based on the carbon bearing the positive charge.

(b)

When we begin studying reactive intermediates, the designation of substitution will be especially important. Label the following carbocations as 1° , 2°, 3°, or 4° or based on the carbon bearing the positive charge.

(c)

Name the following alkanes using the common names for branched substituents.

(c)

Using the Newman projections shown, draw each molecule in its line-angle drawing with all hydrogens and substituents shown. [Carbon b is behind carbon a in these structures.] Wedges and dashes should be used to indicate whether a substituent is coming out of, or going into, the plane of the page.

(b)