1. AP Chemistry: Formation of Esters 530763WW Frey Scientific $47.95 530763WW Frey Scientific $47.95

2. Overview  AP Chem is a year 2 Chem class!! Organic lab possibilities?  For AP Chemistry class (Demo/Combination of labs?)  AP Chem is a year 2 Chem class!! Organic lab possibilities?  For AP Chemistry class (Demo/Combination of labs?)

3. Organic Review (1)  Acetic Acid  Butyric Acid  Acetic Acid  Butyric Acid

4. Organic Review (2)  These acids will react with different alcohols [methyl (1), ethyl (2), butyl (4) & octyl (8)], forming ESTERS (and water).  ESTER:  Esters tend to have sweet, fruity smells, which we will detect in the lab today.  These acids will react with different alcohols [methyl (1), ethyl (2), butyl (4) & octyl (8)], forming ESTERS (and water).  ESTER:  Esters tend to have sweet, fruity smells, which we will detect in the lab today.

5. Organic Review (3)  Example Reaction: CH 3 COOH + CH 3 OH -> CH 3 COOCH 3 + H 2 O  Concentrated Sulfuric Acid will: 1.Act as a Catalyst (make the carbonyl group more electrophilic) 2.Dehydrate the reaction (removing water so more ester can be formed -- LeChatelier)  CAUTION! Use gloves, goggles, and safe lab practices - Conc Sulfuric Acid is 18 M!!  Example Reaction: CH 3 COOH + CH 3 OH -> CH 3 COOCH 3 + H 2 O  Concentrated Sulfuric Acid will: 1.Act as a Catalyst (make the carbonyl group more electrophilic) 2.Dehydrate the reaction (removing water so more ester can be formed -- LeChatelier)  CAUTION! Use gloves, goggles, and safe lab practices - Conc Sulfuric Acid is 18 M!!

6. What We’ll Discover Today  How well/long do the esters keep? (Can this work as a demo in class? Pre-made samples?)  Are all of the scents differentiable? (For future lab modifications - determining identities of unknowns)  Do we REALLY need to pour samples into water? (Just waft, right?! H2O Drives reaction to break down the ester! On the other hand, unreacted sulfuric acid may be a problem if not diluted 1st.)  How well/long do the esters keep? (Can this work as a demo in class? Pre-made samples?)  Are all of the scents differentiable? (For future lab modifications - determining identities of unknowns)  Do we REALLY need to pour samples into water? (Just waft, right?! H2O Drives reaction to break down the ester! On the other hand, unreacted sulfuric acid may be a problem if not diluted 1st.)

7. Lab Setup 1.Break into 8 (EIGHT) groups [1 sample/gp] -- Group # = Sample # 2.Follow procedure steps 3-7 ONLY! 3. 4.Waft. Write scent description. 5.Rotate to all groups - waft & write scent description. ARE THEY DIFFERENTIABLE?! 1.Break into 8 (EIGHT) groups [1 sample/gp] -- Group # = Sample # 2.Follow procedure steps 3-7 ONLY! 3. 4.Waft. Write scent description. 5.Rotate to all groups - waft & write scent description. ARE THEY DIFFERENTIABLE?!

8. Concluding Thoughts 1.Lab procedure and analysis is pretty light for AP Chemistry. (It takes more than C to make a lab worthy of AP Chemistry.) 2.Students synthesizing all samples is a waste of time. 3.Could be modified/added to to bulk up the difficulty & analysis. Unknown samples? End of year lab? 1.Lab procedure and analysis is pretty light for AP Chemistry. (It takes more than C to make a lab worthy of AP Chemistry.) 2.Students synthesizing all samples is a waste of time. 3.Could be modified/added to to bulk up the difficulty & analysis. Unknown samples? End of year lab?

9. Suggestions? Ideas? Modifications?

10. Ref  http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Acetic_acid_atoms.svg/8 00px-Acetic_acid_atoms.svg.png http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Acetic_acid_atoms.svg/8 00px-Acetic_acid_atoms.svg.png  http://www.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/common s/2/24/Butyric-acid-2D- skeletal.png&imgrefurl=http://commons.wikimedia.org/wiki/File:Butyric-acid-2D- skeletal.png&usg=__ysSaPc_- P1BeP6q54i03joE0qbI=&h=576&w=1100&sz=20&hl=en&start=3&um=1&itbs=1&tbnid=KreQ1 sPhh4D_AM:&tbnh=79&tbnw=150&prev=/images%3Fq%3Dbutyric%2Bacid%26um%3D1%26hl% 3Den%26client%3Dsafari%26sa%3DN%26rls%3Den%26tbs%3Disch:1  http://www.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/common s/9/99/Ester-skeletal.png&imgrefurl=http://commons.wikimedia.org/wiki/File:Ester- skeletal.png&usg=__KXMDdMXsC_ghX4Hqvb-B8VI_- D4=&h=744&w=969&sz=11&hl=en&start=3&um=1&itbs=1&tbnid=gmd_CISuVsAuAM:&tbnh=1 14&tbnw=148&prev=/images%3Fq%3Dester%26um%3D1%26hl%3Den%26client%3Dsafari%26s a%3DN%26rls%3Den%26tbs%3Disch:1   http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Acetic_acid_atoms.svg/8 00px-Acetic_acid_atoms.svg.png http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Acetic_acid_atoms.svg/8 00px-Acetic_acid_atoms.svg.png  http://www.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/common s/2/24/Butyric-acid-2D- skeletal.png&imgrefurl=http://commons.wikimedia.org/wiki/File:Butyric-acid-2D- skeletal.png&usg=__ysSaPc_- P1BeP6q54i03joE0qbI=&h=576&w=1100&sz=20&hl=en&start=3&um=1&itbs=1&tbnid=KreQ1 sPhh4D_AM:&tbnh=79&tbnw=150&prev=/images%3Fq%3Dbutyric%2Bacid%26um%3D1%26hl% 3Den%26client%3Dsafari%26sa%3DN%26rls%3Den%26tbs%3Disch:1  http://www.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/common s/9/99/Ester-skeletal.png&imgrefurl=http://commons.wikimedia.org/wiki/File:Ester- skeletal.png&usg=__KXMDdMXsC_ghX4Hqvb-B8VI_- D4=&h=744&w=969&sz=11&hl=en&start=3&um=1&itbs=1&tbnid=gmd_CISuVsAuAM:&tbnh=1 14&tbnw=148&prev=/images%3Fq%3Dester%26um%3D1%26hl%3Den%26client%3Dsafari%26s a%3DN%26rls%3Den%26tbs%3Disch:1 