VISUAL SKILLS Visualize the structural formula of each of the following hydrocarbons. Which hydrocarbon has a double bond in its carbon skeleton?a. C3H8b. C2H6c. C2H4d. C2H2

The two compounds


are related to each other by being __________.

A molecule has one carbon-carbon double bond and four monovalent atoms or groups. How many different cis-trans isomers exist for this molecule?

Pharmaceutical companies are selling billions of dollars' worth of single-enantiomer drugs. Why might it be important to use only one form of an enantiomer?

Organic chemistry is currently defined asa. the study of compounds made only by living cells.b. the study of carbon compounds.c. the study of natural (as opposed to synthetic) compounds.d. the study of hydrocarbons.

VISUAL SKILLS Identify the asymmetric carbon in this molecule:

VISUAL SKILLS Which of the molecules shown in question 5 has an asymmetric carbon? Which carbon is asymmetric?

The diversity of life is staggering. Yet the molecular logic of life is simple and elegant: Small molecules common to all organisms are ordered into unique macromolecules. Explain why carbon is central to this diversity of organic molecules. How do carbon skeletons, chemical groups, monomers, and polymers relate to this molecular logic of life?