1. For one of the models, find the chiral carbon atom in the ibuprofen portion of the salt. Draw a Newman projection about the bond between the chiral carbon atom and its adjacent methyl group. Repeat for the other salt. How are these two Newman projections similar or different?

2. Ibuprofen takes part of its name from the iso-butyl group, the 4-carbon chain at one end of the molecule. The condensed structure for the iso-butyl group is (CH3)2CH—CH2—. For each of the models, draw the Newman projection about the methine (CH)—methylene (CH2) bond. Are the two Newman projections the same or are they different? Do they represent the lowest energy conformation? Explain your answer.

3. Identify the two salts by their stereochemistry. Which one is the (S,S) salt and which is the (R,S) salt?