What are the IUPAC names for the following carboxylic acids: a) CH3CH(CH3)CH2COOH b) CH3CH(CH3)CH2CH2COOH c) CH3CH2CH(CH2CH3)CH2CH2COOH?

Here are the names for the given carboxylic acids, following IUPAC rules:

• a) The longest continuous carbon chain containing the carboxyl group is 4 carbons long (butane). The methyl group is at position 2.

  $$\boxed{\text{2-methylbutanoic acid}}$$

• b) The longest continuous carbon chain containing the carboxyl group is 5 carbons long (pentane). The methyl group is at position 2.

  $$\boxed{\text{2-methylpentanoic acid}}$$

• c) The longest continuous carbon chain containing the carboxyl group is 6 carbons long (hexane). The ethyl group is at position 3.