General organic and biological chemistry structures off life 5th CH16 carboxylic acids GOB structures 5th ed

Lecture Presentation Chapter 16 Carboxylic Acids and Esters Karen C Timberlake General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chapter 16 Carboxylic Acids and Esters Surgical technicians prepare the operating room and the patients for surgery by • • creating a sterile environment in the surgical room washing, shaving, and disinfecting incision sites During the surgery, a surgical technician provides the sterile instruments and supplies to the surgeons and surgical assistants General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Chapter 16 Readiness Core Chemistry Skills • Writing Equations for Reactions of Acids and Bases (11.7) • Naming and Drawing Alkanes (12.2) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc 16.1 Carboxylic Acids A carboxylic acid contains a carboxyl group, which consists of a hydroxyl group —OH attached to the carbon in a carbonyl group Learning Goal Write the IUPAC and common names for carboxylic acids, and draw their condensed and line-angle structural formulas General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc IUPAC Names for Carboxylic Acids In the IUPAC names of carboxylic acids, • the e in the alkane name is replaced with oic acid CH4 Methane Methanoic acid CH3—CH3 Ethane Ethanoic acid General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc IUPAC Names for Carboxylic Acids Substituents are numbered from the carboxyl, which is carbon General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc IUPAC Names for Carboxylic Acids • As before, for benzoic acid, the placement of substituents is shown using the prefixes ortho, meta, and para General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc IUPAC Names for Carboxylic Acids Many carboxylic acids are still named by their common names, which use prefixes: form, acet, propion, butyr • When using the common names, the Greek letters alpha (α), beta (β), and gamma (γ) are assigned to the carbons adjacent to the carboxyl carbon General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Common Carboxylic Acids A red ant sting contains methanoic acid (formic acid) that irritates the skin The sour taste of vinegar is due to ethanoic acid (acetic acid) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Guide to Naming Carboxylic Acids General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Esters in Fruits • Many of the fragrances of perfumes and flowers and the flavors of fruits are due to esters • Small esters are volatile, so we can smell them, and they are soluble in water, so we can taste them • The odor of grapes is due to ethyl heptanoate General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Esters in Fruits and Flavoring General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Study Check Draw the condensed structural formulas for each of the following compounds: A propyl pentanoate B ethyl propionate General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Solution Draw the condensed structural formulas for each of the following compounds: A propyl pentanoate B ethyl propionate General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc 16.5 Properties of Esters Ethyl acetate is the solvent in fingernail polish, plastics, and lacquers Learning Goal Describe the boiling points and solubility of esters; draw the condensed structural formulas for the hydrolysis products General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Boiling Points of Esters Esters have • • boiling points higher than those of alkanes and ethers boiling points lower than those of alcohols and carboxylic acids of similar mass Because ester molecules not have hydroxyl groups, they cannot hydrogen bond to each other General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Solubility of Esters in Water • Esters are soluble if they have two to five carbon atoms As the number of carbons increases from five, their solubility in water decreases • The partially negative oxygen of the carbonyl group forms hydrogen bonds with the partially positive hydrogen atoms of water molecules General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Acid Hydrolysis of Esters In acid hydrolysis, • an ester reacts with water to produce a carboxylic acid and an alcohol • a water molecule provides an —OH group to convert the carbonyl group of the ester to a carboxyl group • an acid catalyst and heat are required General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Acid Hydrolysis of Esters Aspirin that has been stored for a long time may undergo hydrolysis in the presence of water and heat General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Base Hydrolysis (Saponification) Base hydrolysis, or saponification, • • is the reaction of an ester with a strong base in the presence of heat produces a carboxylate salt and an alcohol General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Solution Ethyl acetate is a solvent used in fingernail polish, plastics, and lacquers Write the balanced chemical equation for the hydrolysis of ethyl acetate with NaOH ANALYZE Given Need THE ester, base carboxylate salt PROBLEM and alcohol Write equation for reaction of ethyl acetate and NaOH, in sample problem 16.8 General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Study Check Write the balanced chemical equation when methyl acetate reacts with A water, heat, and an acid catalyst B KOH and heat General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Solution Write the balanced chemical equation when methyl acetate reacts with A water, heat, and an acid catalyst B KOH and heat General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Concept Map General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc ... in combination General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc General, Organic, and Biological Chemistry: Structures of Life,... acid) General, Organic, and Biological Chemistry: Structures of Life, 5/e Karen C Timberlake © 2016 Pearson Education, Inc Guide to Naming Carboxylic Acids General, Organic, and Biological Chemistry: ... 16 Readiness Core Chemistry Skills • Writing Equations for Reactions of Acids and Bases (11.7) • Naming and Drawing Alkanes (12.2) General, Organic, and Biological Chemistry: Structures of Life,