1 © 2013 Pearson Education, Inc. Chapter 16, Section 1 General, Organic, and Biological Chemistry Fourth Edition Karen Timberlake 16.1 Carboxylic Acids Chapter 16 Carboxylic Acids and Ethers © 2013 Pearson Education, Inc. Lectures

2 © 2013 Pearson Education, Inc. Chapter 16, Section 1 A carboxylic acid contains a a hydroxyl group (–OH) attached to a carboxyl group, which is a carbonyl group. Carboxylic Acids © 2013 Pearson, Education Inc.

3 © 2013 Pearson Education, Inc. Chapter 16, Section 1 IUPAC Names of Carboxylic Acids

4 © 2013 Pearson Education, Inc. Chapter 16, Section 1 IUPAC Names of Carboxylic Acids The name of the carboxylic acid of benzene, is benzoic acid.  The carbon in the carbonyl group is bonded to. carbon 1 in the benzene ring.  The ring is numbered to give the lowest possible. numbers for any substituents.  The prefixes ortho, meta, and para may be used to. show the position of one other substituent.

5 © 2013 Pearson Education, Inc. Chapter 16, Section 1 IUPAC Names of Carboxylic Acids The prefixes ortho, meta, and para may be used to show the position of one other substituent. Insert diagram of benzoic acid, 4-aminobenzoic acid and 3,4- dichlorobenzoic acid bottom pg 571 with labels.

6 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Common Names of Carboxylic Acids  Many carboxylic acids are still named by their common names that include prefixes, form, acet, propion, butyr.  When using the common names, the Greek letters alpha (  ), beta (  ), and gamma (  ) are assigned to the carbons adjacent to the carboxyl carbon.

7 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Formic Acid A red ant sting contains formic acid that irritates the skin.

8 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Guide to Naming Carboxylic Acids

9 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Give the IUPAC and common name for each carboxylic acid. IUPAC Names for Carboxylic Acids

10 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Give the IUPAC and common name for each carboxylic acid. Analyze the Problem. IUPAC Names for Carboxylic Acids Functional Group IUPAC NamingName carboxylic acidChange the -e of the alkane name to -oic acid and count from carbon 1 of the carboxyl group for any substituents. Alkanoic acid

11 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Give the IUPAC and common name for each carboxylic acid. Step 1 Identify the longest carbon chain and replace the -e in the corresponding alkane name with -oic acid. butanoic acid benzoic acid IUPAC Names for Carboxylic Acids

12 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Give the IUPAC and common name for each carboxylic acid. Step 2 Give the location and name of each substituent by counting the carboxyl carbon as 1. a. 2-methylbutanoic acid b. 3-chlorobenzoic acid  -methylbutyric acid meta-chlorobenzoic acid IUPAC Names for Carboxylic Acids

13 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Alpha Hydroxy Acids Alpha hydroxy acids (AHAs)  occur naturally in. fruit, milk, and. sugar cane.  are used in skin. care products.

14 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Give the IUPAC and common names for each of the following. A. B. C. Learning Check

15 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Give the IUPAC and common names for each of the following. A. B. C. Solution 2-Bromobenzoic acid (o-bromobenzoic acid) 2-Methylpropanoic acid (  -methylpropionic acid) ethanoic acid (acetic acid)

16 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Preparation of Carboxylic Acids Carboxylic acids are prepared  by oxidizing primary alcohols or aldehydes.  from the oxidation of ethanol, which produces ethanoic acid (acetic acid). © 2013 Pearson Education, Inc.

17 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Esters  differ from carboxylic acids by the replacement of H in the hydroxyl group with an alkyl group.  are fragrant components of many fruits, such as bananas, oranges, and strawberries.

18 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Esterification is the reaction of a carboxylic acid and alcohol in the presence of an acid catalyst to produce an ester. Insert esterification reaction pg 580 Esterification

19 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Acetylsalicylic Acid Aspirin  is used to relieve pain and reduce inflammation.  is an ester of salicylic acid and acetic acid.  is derived from the bark of a willow tree.

20 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Acetylsalicylic Acid In 1899, Bayer chemical company in Germany produced an ester of salicylic acid and acetic acid, called acetylsalicylic acid (aspirin) that was less irritating to the stomach than salicylic acid.

21 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Methyl Salicylate Oil of wintergreen  is used to soothe sore muscles.  has a pungent, minty odor.  is an ester of salicylic acid and methanol.

22 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Polyester Terephthalic acid (an acid with two carboxyl groups) reacts with ethylene glycol to form ester bonds on both ends of the molecules. This allows them to combine forming long chains of molecules called polyester.

23 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Esters in Plants Esters give flowers and fruits their pleasant fragrances and flavors.

24 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Guide to Naming Esters

25 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Naming Esters The name of an ester contains the names of  the alkyl group from the alcohol, and  the carbon chain from the acid with -ate ending.

26 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Learning Check Give the IUPAC and common name of the following ester, responsible for the flavor and odor of pears.

27 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Give the IUPAC and common name of the following ester, responsible for the flavor and odor of pears. Step 1 Write the name of the carbon chain from the alcohol as an alkyl group. propyl from 1-propanol Solution

28 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Give the IUPAC and common name of the following ester, responsible for the flavor and odor of pears. Step 2 Change the -ic acid of the acid name to -ate. Ethanoate (acetate) Propyl ethanoate (IUPAC name) Propyl acetate (common name) Solution

29 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Boiling Points of Esters The boiling points of esters  are higher than for alkanes of similar mass.  are lower than alcohols and carboxylic acids of similar mass because esters cannot form hydrogen bonds with each other.

30 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Solubility in Water Esters  are soluble in water when they have 1–5 carbon atoms.  form hydrogen bonds from the partial negatively charged carbonyl oxygen to the partial positively charged hydrogen atoms in water.  decrease their solubility in water with an increase in the number of carbon atoms.

31 © 2013 Pearson Education, Inc. Chapter 16, Section 1 In acid hydrolysis,  an ester reacts with water to produce a carboxylic acid and an alcohol.  a strong acid catalyst is required. Acid Hydrolysis of Esters

32 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Base hydrolysis (also called saponification)  is the reaction of an ester with a strong base.  produces the salt of the carboxylic acid and an alcohol. Base Hydrolysis (Saponification)

33 © 2013 Pearson Education, Inc. Chapter 16, Section 1 “Soaps” The base hydrolysis of long-chain fatty acids produces acid salts called “soaps.”

34 © 2013 Pearson Education, Inc. Chapter 16, Section 1 Cleaning Action of Soap A soap  contains a nonpolar end that dissolves in nonpolar fats and oils and a polar end that dissolves in water.  forms groups of soap molecules called micelles that dissolve in water and are washed away.