Chem 213 Ochem Laboratory Experiments]

Spring 2018 [CHEM 213 OCHEM LABORATORY EXPERIMENTS]

Experiments & Exam Schedule ~Spring 2018~

Date What’s due? Week Exp.# Topic 2018 Prelab (PL), Report (R) Safety Contract, Check-in Introduction, Safety, Check-in 1 1-16 16 Sheet, PL 16 How to write-up a Lab Experiment using EXP 16 2 1-23 17 PL: 17 Nitration of Methyl Benzoate 3 1-30 18 PL: 18, R: 17 Friedel-Crafts Acylation 4 2-6 R: 18 Exam 1 Exam 1 review

5 2-13 19 PL: 19 Reactions of Alcohols & Phenols 6 2-21* 20 * Due Wed: PL: 20, R: 19 Synthesis of Alkenes 7 2-27 21 PL: 21, R: 20 Reduction of Ketone to form a Diol 8 3-6 R: 21 EXAM 2 Exam 2 review

Spring Break 3-12 to 3-17

9 3-20 22 PL: 22 Aldol Condensation

10 3-27 23 PL: 23, R:22 Reactions of Aldehydes & Ketones Lecture

11 4-3 R: 23 EXAM 3 12 4-10 Nothing Campus Closed Tuesday April 10 13 4-17 24 PL: 24 Isolation of Milk Protein 14 4-24 25 R: 24, PL 25, R:25 Soap Synthesis & Check-out 15 5-1 Nothing EXAM 4 16 5- 7 & 8 Monday May 7: Poster due Tuesday May 8: Application Project Poster Session 17 Return Loaned Books: You must turn in loaned 18 5-21? books before final exam to get a final exam. Final Exam (TBD) ______@ 7:30 am All papers, exam reviews, experiment prelabs (PL) and lab reports (R), are due before 7:20 am. NO LATE REPORTS OR PAPERS ACCEPTED. Technological problems (printer, computer, ink, etc.) are not acceptable excuses for late reports or papers, so start early.

Labs: For each experiment you are responsible to prepare and read over lab text and lab notes to understand the general principles. You are required to turn in a purpose and procedure for the experiment before lab starts. The purpose and procedure is written in your lab notebook and the carbon copy given to me. If you do not turn in the purpose/procedure on time, you will not be able to perform that experiment (No makeup labs allowed). I will start every lab with a short discussion of safety and lab technique. If you arrive late, I cannot allow you to perform the experiment. I will not tell you how to do the experiment step by step. You are responsible to have read the material with an understanding of the experiment and what you need to do before you come to lab. If I feel you are unprepared for the lab, you will be asked to leave without credit for the experiment and no makeup lab allowed.

APPLICATION PROJECT (60 PTS) You will complete research and present a poster to the class. Key Due Dates and Times Topic Approved by Instructor: Monday March 26th (each day late -5 points) You must post your organic compound on the Discussion Board in Blackboard; each student must have a different compound) Poster turned into lab room: Before Monday May 7th @ 7:20 am (Early posters encouraged, do not be late to lecture) th Poster Session: (Attendance mandatory) Tuesday May 8 @ 7:30 am

Only use analytical balances for this course for ALL mass measurements. Issued Laboratory Equipment: The student is responsible for all issued equipment as well as the key. Points may be deducted for missing or broken equipment and/or key. Point values will be determined by the instructor. The student is responsible for taking an inventory of the drawer and hood equipment during both the check-in and check-out process or when dropping the course. The student is responsible for the cleaning of all equipment after each experiment and also at the time of check-out. Any student failing to check-out of issued lab drawer and taking inventory of equipment may result in a hold being placed on transcripts and registration.

Dress Code for Lab: Eye protection must be worn at all times anyone is performing an experiment in lab, even if you are finished. Goggles or safety glasses may be purchased from the bookstore or hardware store. Goggles will fit over prescription glasses. If you wear shorts or skirts to class, it must be knee length, or you must wear an apron or lab coat. You must provide your own, the bookstore will have some available for purchase. No opened toe shoes, exposed tops of feet, nor sandals may be worn in the lab.

Refusal to comply with the above rules will result in your earning a zero grade for the experiment for that day, and you will not be allowed to do a make-up for missed work.

Laboratory Report: Each experiment completed correctly and handed in on time will be graded on a 20-point basis. All experiment reports due approximately 1 week after lab is scheduled, before the lab or exam starts (see page 1 for due dates). Late reports will not be accepted for any reason. If you know you cannot attend, then you may have a student turn in the report on time for you. All experiments include spectroscopy this term.

What is due before or at the end of lab for the Lab Report: a) Purpose: Written in your lab notebook along with the procedure, and the copy turned in before the lab starts Read the experiment to determine what the purpose of the experiment is. The purpose is the reason for doing the experiment, and it is a couple of sentences, or a short paragraph. The purpose should also include the name(s) of the reactants and/or products and must include any reactions, or equations for the experiment. If MP or % yield will be determined, include a statement such as “purity of product will be determined using melting point range’, and/or “percent yield of product will be calculated”. (2 pts) b) Procedure: Also written in your lab notebook along with the purpose, and the copy turned into me before the lab starts. The procedure must be in enough detail, so that the experiment can be performed from just your notes. This must include materials list and equipment needed, and a brief sketch of the lab apparatus or set up with each piece clearly labelled. This is turned in before the experiment is performed. (3pts) c) Data: This is written in your lab notebook. It should be prepared before you come to lab so that during the experiment, all you need to do is fill in the data and turn in the copy to me as you leave, at the end of lab. Be sure to write this on a separate page in your notebook from your purpose and procedure, since this is turned in at a different time. I do not return these to you. (1 pt)

What is due the following week for the Lab Report: Report: The front and first page is the Report page from this packet where you write your name, (for Exp 16 that is page 4). Complete all sections and questions on the report page, including the spectroscopy sections in the space provided. Do not write answers to questions in the lab notebook. Then attach the page(s) written in your lab notebook, clearly label each section: Calculations, Graphs, Conclusion*, and Sources of Error.

*The conclusion must include results such as MP, unknown number and identity, % yield, etc. Questions on the report pages need to be answered directly on that page, and not written in lab notebook. (14 pts)

You are responsible for understanding the information in your Zubrick lab text. The lab text is your guide to organic lab techniques required for this course. For example, if the directions ask you to recrystallize, look up recrystallization techniques in your lab text. Standard laboratory techniques, safety, and brief theoretical discussions are described in the text. It is your responsibility to read and understand the information before you come into lab to perform the experiments. If I feel you are not properly prepared for the experiment, you will be asked to leave the lab, no credit will be given for the experiment, and no make-up lab is allowed. Copyright © 2018 K. Boebinger 2 Spring 2018 [CHEM 213 OCHEM LABORATORY EXPERIMENTS]

Experiment 16: Synthesis of trans-Cinnamic Acid

Carboxylic acids are the most common class of organic acids that are encountered. The pKa values of carboxylic acids range 3-5, classifying them as weak acids. Phenols are only slightly less acidic, while alcohols, ketones and terminal alkynes are much less acidic.

This experiment will synthesize a carboxylic acid from an iodoform reaction of a methyl ketone; the reaction will result in a loss of a carbon from the chain. The oxidizing agent is commercial bleach which contains 5% hypochlorite. This synthesis will take place in two steps;

Reaction 1st A haloform reaction using hypochlorite (NaOCl) as the oxidizing agent

NaOCl + HOH + NaCl 2 NaOH + Cl2

2nd Oxidation of the methyl ketone to a carboxylic acid. O O H+ O + NaOCl (Cl2, NaOH) CHCl + C C C 3 - + R CH R O Na R OH 3 H O H O 1. NaOCl, H2O C C C C C CH C OH + CHCl3 3 2. H+ H H trans -4-phenyl-3-buten-2-one trans-cinnamic acid MM = 146.19 g/mol MM 148.2 g/mol

Procedure: 1. Place 0.300 g trans-4-phenyl-3-buten-2-one (benzalacetone) and one boiling stone in a 10-mL round bottom flask (You will Not be using the conical vial or spin vane as shown in the picture, be sure to draw the round bottom flask in your sketch for the prelab). 2. Add 1 mL THF and stir to dissolve. 3. Carefully and without stirring, add 3.0 mL fresh bleach and two drops 50% NaOH (Caution: wear gloves and avoid spills). Do not stir or mix yet. 4. Fit a water-jacket condenser on the flask, turn on the water to the condenser, then stir contents vigorously, and reflux the mixture for 30 minutes (start timing after boiling starts) in a sand bath at a low heat setting. Do NOT set the dial above 4 on the hot plate. Do not let the solution get too hot, or super-heat. You can cover sand bath with foil to keep in heat, but check it often. Thermometer is optional. 5. Cool to room temperature; transfer the contents to a centrifuge tube (pictured on right). 6. Add 25 mg sodium sulfite to remove any unreacted oxidizing agent, swirl. 7. Add 4 mL diethyl ether and 1.5 – 2.0 mL water to the tube. Cork tube and then shake. Add more water if necessary to help break up the emulsion. Place the tube in a 125-mL Erlenmeyer flask to rest until two distinct layers form. 8. Use a Pasteur pipet to transfer the bottom aqueous layer to a clean 25-mL Erlenmeyer flask (keep). Be careful not to remove solid from bottom (unreacted Na2SO3 from step 6, now waste). Properly dispose of the diethyl ether (top layer, and solid) in waste. 9. Add 3M HCl drop wise to the aqueous solution to pH 3 to precipitate the product. Test the pH frequently by using a capillary tube, dip it in the solution, and then touch it to pH paper to determine pH. (About 20-25 drops of HCl will be required). Troubleshooting: If a precipitate doesn’t form after correct pH is reached: use an ice bath, scratch bottom of flask with stirring rod, go back to step 6 with your aqueous solution. 10. Collect the solid by vacuum filtration using a Hirsch funnel (pictured on right). Be sure to weigh filter paper. Wash the precipitate with cold water. 11. Allow crystals to completely dry, weigh, and determine purity using melting point range and calculate percent yield of product.

Report: Experiment 16 Name: ______Synthesis of trans-Cinnamic Acid Lab Day ______Date ______

Data: Mass trans-4-phenyl-3- Mass filter paper Mass Filter paper & Mass trans-cinnamic buten-2-one trans-cinnamic acid acid synthesized synthesized

g g g g

Literature MP Range trans-cinnamic acid Experimental MP range trans-cinnamic acid

oC oC

Questions & Calculations: (Show all calculations in lab notebook)

1. Calculate initial moles of benzalacetone 2. Calculate theoretical yield & percent yield of product (this is the limiting reagent) (trans-cinnamic acid) using the limiting reagent. Theoretical Yield Molar Mass g/mol g Product Percent Yield of Initial Mole mol % Product

3. Write the dissociation reaction in water, and equilibrium expression (Ka) for trans-cinnamic acid. (Note: This is material from General Chemistry, you may want to look it up in that text or search on internet) Dissociation Reaction

Equilibrium Expression

CHEM 213 ~ Experiment 16: Spectroscopy

1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

2. On each of the spectra provided, Identify: Parent Peak, Base Peak, fragment losses with proposed fragments, and fragment signals with proposed structures in the MS for the compound. trans- cinnamic acid C9H8O2 Structure:

MM=

CNMR 3. Draw the structure for the compound. Label each carbon type with either numbers or letters. 4. How many different carbon types are in the compound? 5. Clearly label: a. On the spectrum given identify each signal with a specific carbon, and ppm value. b. On the structure you drew, label each carbon with the ppm signal value. trans- cinnamic acid C9H8O2

HNMR 6. Draw the structure for the compound. Label each hydrogen type with either numbers or letters. 7. How many different hydrogen types are in the compound? 8. Clearly label: a. On the spectrum given identify each signal with a specific hydrogen, and ppm value. b. On the structure you drew, label each hydrogen with the ppm signal value. trans- cinnamic acid C9H8O2: Number of nonequivalent hydrogens =

IR 9. List the functional groups and signals that can be identified in this IR spectrum for the compound. 10. On the IR spectrum, clearly label the signals for the major functional groups, identify the fingerprint region. trans- cinnamic acid C9H8O2

List the functional groups

Experiment 17: Nitration of Methyl Benzoate Electrophilic Aromatic Substitution

Aromatic compounds are very stable and the primary reactions they undergo are electrophilic substitutions. One of the features of electrophilic substitution is the influence of substituents on the aromatic ring. The group already present will direct the incoming group to a particular location on the ring, either ortho and para or meta. Ester groups exert a directive effect in the nitration of methyl benzoate. In this experiment, the electrophile is the + nitronium ion (NO2 ), the aromatic compound is methyl benzoate, and the substitution is the replacement of hydrogen with a nitro group.

CH3 CH3 Reaction: O O O O C C H SO 2 4 + HNO + HOH 3 NO2

methyl benzoate mononitrated product

You will determine the identity of the mono-nitrated product formed in this reaction based on the melting point of the recrystallized product. The melting points of the three isometric methyl nitrobenzoates are methyl 2-nitrobenzoate (-13 oC), methyl 3-nitrobenzoate (78 oC), methyl 4-nitrobenzoate (95 oC).

Procedure: Miniscale

1. Prepare an ice bath in a 100-mL beaker on a magnetic stir plate. 2. Carefully immerse a clean, dry 25-mL Erlenmeyer flask which contains a spin bar or triangle into the ice bath. Ice level should be about half way up the flask. 3. Pipet 1.0 mL (1.09 g) methyl benzoate into the flask. 5 6 5 6 4 7 4 7 3 8 3 8 2 9 2 9 11 4. Carefully add 2.25 mL concentrated (18 M) H2SO4 to the flask, begin stirring. NO HEAT. 1 1 1 0 It may be necessary to use a clamp on top to keep the beaker straight and from floating. 5. Set up a second ice bath in a 250-mL beaker. 6. Prepare the nitrating solution by adding 0.75 mL concentrated sulfuric acid 0.75 mL concentrated (16 M) nitric acid to a clean dry small test tube. Cool the mixture in an ice bath. 7. Using a Pasteur pipet, slowly add (this should take about 15 min.) the cooled sulfuric acid - nitric acid mixture to the stirring solution of methyl benzoate. Adding the nitrating reagent too fast will increase the amount of by-products, and decrease your yield. 8. After all the nitrating agent has been added, carefully remove from the ice bath. 9. Stir the solution until it has come to room temperature. 10. Let the flask stand undisturbed for 15 minutes. 11. While waiting, set up five clean small test tubes for use in the transfer of product and washing the precipitate. Add 5 mL water to each of three test tubes, and 1.5 mL methanol to the each of the other two. Place in the ice bath to get cold. 12. Using a Pasteur pipet, pour the mixture, with stirring, over 30 grams of crushed ice contained in a 150-mL beaker. 13. Rinse the flask with 5 mL of cold water and add to the beaker which contains the ice. Allow the ice to melt. 14. Vacuum filter the precipitate using a Bucher funnel (do not weigh this filter paper). Wash the crystals with three separate 5 mL portions of cold water, then two 1.5 mL portions of cold methanol. 15. Recrystallize the crude product from methanol. (Add 2 mL methanol then heat to dissolve, may need up to 4 mL. After dissolving place in ice bath to recrystallize). (Technique in lab text Ch. 13) 16. Vacuum filter, use minimal cold methanol to transfer and wash. Use a new, clean filter paper (weigh paper). 17. Allow crystals to completely dry, weigh, and determine melting point range. Use MP to identify product and determine purity. Calculate percent yield of product.

Be sure to show all calculations in lab notebook, along with your conclusion and sources of error.

Report: Experiment 17 Name: ______Nitration of Methyl Benzoate Lab Day ______Date ______

Data: Mass of Total Volume Mass of Mass methyl Mass of Filter Paper Melting Point Volume (16 M) Product benzoate (18 M) Filter Paper and Dried Range of Product nitric acid Recovered H2SO4 Product o g mL mL g g g C

Questions & Calculations: (Show all calculations in lab notebook)

1. Based on your melting point results, what is the name of the major product formed in this reaction?

2. Complete the table HNO H SO methyl benzoate using your data 3 2 4 Molar Mass (g/mol)

Initial Mole (mol)

3. Calculate theoretical yield & percent yield of product using the limiting reagent. (Note mole ratio) Name the limiting reagent Theoretical Yield Product Percent Yield Product

g %

Questions: 4. List and explain 2 reasons why is ice cold methanol used to wash product.

5. Write a complete mechanism for the formation of the observed product. Be sure to include a separate mechanism for the preparation of the catalyst, then a second mechanism showing how catalyst is involved.

CHEM 213 ~ Experiment 17: Spectroscopy 1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

MM=

HNMR 6. Draw the structure for the compound. Label each hydrogen type with either numbers or letters. 7. How many different hydrogen types are in the compound? 8. Clearly label: a. On the spectrum given identify each signal with a specific hydrogen, and ppm value. b. On the structure you drew, label each hydrogen with the ppm signal value. methyl benzoate C8H8O2: Number of nonequivalent hydrogens =

List the functional groups

Experiment 18: Friedel-Crafts Acylation Electrophilic Aromatic Substitution

The Friedel-Crafts reactions are a set of reactions developed by Charles Friedel and James Crafts in 1877. There are two main types of Friedel-Crafts reactions: alkylation reactions and acylation reactions. This reaction type is part of electrophilic aromatic substitution.

Friedel-Crafts acylation is the acylation of an aromatic ring with an acyl chloride using a strong Lewis acid catalyst. Reaction conditions are similar to the Friedel-Crafts alkylation. This reaction has several advantages over the alkylation reaction. Due to the electron-withdrawing effect of the carbonyl group, the ketone product is always less reactive than the original molecule, so multiple acylations do not occur. Also, there are no carbocation rearrangements as an aromatic carbocation is very stable compared to alkyl carbocations.

AlCl O Reaction: O 3 C CH3 + Cl C CH3 CH Cl 2 2 Biphenyl 4-acetylbiphenyl MM = A practical illustration of Friedel-Crafts acylation is the reaction of biphenyl using acetyl chloride. Because of the large size of the phenyl substituent, an ortho-para directing group, the para product is the principle isomer.

Procedure: NOTE: You have two pre-lab calculations for this experiment, see report. 1. Before starting: All glassware to be used in this experiment must be dried in an oven, use Al pie tin to hold glassware. Cool all glassware to room temperature after drying. 2. Add 1.25 mmol anhydrous aluminum chloride and 2.00 mL methylene chloride to a 5-mL conical vial with a spin vane. (Use petri dish for sand bath, metal pan may keep spin vane from moving). 3. Next, add 0.500 mmol powdered biphenyl (crush if pieces are large into smaller pieces), then pipet 50 μL acetyl chloride to the vial. 4. Set up the reflux apparatus (Figure 23.1, right side) use a water condenser with water flowing, not an air condenser. The drying tube contains fresh granular CaCl2 (tube might already be prepared for you). 5. Place the reaction vessel in a sand bath on a hot plate/stirrer and stir at room temperature for 5+ minutes. Solid may take a little time to dissolve, be patient, but after 10 minutes, some may remain undissolved and move on to next step. 6. Reflux the mixture with heat and stirring for an additional 10 minutes. 7. Remove from sand bath and allow cooling to room temperature. 8. Place in an ice bath; carefully and slowly add 1.00 mL 3 M HCl drop-wise to the vial. 9. Using tweezers, remove spin vane, cap the vial and shake (do not invert) with venting. Any remaining AlCl3 should dissolve in the aqueous layer. 10. Draw off the bottom layer with a Pasteur pipet and save. Remove the aqueous layer remaining in the vial to a “waste” beaker and save until the end of the experiment. 11. Place the organic layer back in the vial, then add 1.00 mL 1M NaOH to the vial, cap and shake with venting. 12. Remove the organic layer and transfer to another vial. Draw off and discard the aqueous layer to the “waste” beaker. 13. Add 1 mL H2O to the vial with the organic layer; repeat the washing procedure from step 11. 14. Draw off the organic layer and place in a 10-mL beaker. Dry the organic layer over anhydrous sodium sulfate. (When the drying agent starts to clump, then enough has been added). Transfer the dry organic solution to a clean, dry 25-mL Erlenmeyer flask using a filter pipet, use minimal cotton so it doesn’t absorb all the solution. (pg 69 Fig. 7.2 a) 15. Allow the methylene chloride to evaporate under a hood to give crude solid product. May be colorless and hard to see. 16. Recrystallize (see chapter 13 for details) from ethanol using an Erlenmeyer flask and Hirsch funnel. 17. Allow crystals to completely dry, weigh, and determine purity using melting point range and calculate percent yield of product.

Report: Experiment 18 Name: ______Friedel-Crafts Acylation Lab Day ______Date ______

Pre-lab Calculations (write these in your prelab notebook), and check with instructor before you proceed):

1. Calculate the mass of 1.25 mmol anhydrous AlCl3. ______g

2. Calculate the mass of 0.500 mmol powdered biphenyl ______g

Experimental Data:

Mass Recrystallized Product and Filter Paper ______g

Mass of Filter Paper ______g

Mass of Recrystallized Product ______g

Melting Point Range of Recrystallized Product ______oC

True MP Range of Product from literature ______oC

Questions:

1. Indicate volume and/or mass used and calculate initial mole and for all reactants.

Reagent Volume (μL) Mass (g) Mole (mol) Biphenyl Acetyl chloride Aluminum chloride

2. Calculate theoretical yield of product in mass using the limiting reagent.

Limiting Reagent ______g

3. Calculate percent yield of product ______%

4. Based on yield obtained of product, how successful was the preparation, and at what points in the procedure may have product been lost?

5. Explain why the para product is the principle isomer formed.

CHEM 213 ~ Experiment 18: Spectroscopy 1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

2. On each of the spectra provided, Identify: Parent Peak, Base Peak, fragment losses with proposed fragments, and fragment signals with proposed structures in the MS for the compound.

4-acetylbiphenyl C14H12O Structure:

MM=

4-acetylbiphenyl C14H12O: Number of nonequivalent carbons =

4-acetylbiphenyl C14H12O: Number of nonequivalent hydrogens =

4-acetylbiphenyl C14H12O

List the functional groups

Experiment 19: The Hydroxyl Group- Reactions of Alcohols and Phenols

Alcohol, any of a class of organic compounds characterized by one or more hydroxyl (−OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain). Alcohols may be considered as organic derivatives of water (H2O) in which one of the hydrogen atoms has been replaced by an alkyl group, typically represented by R in organic structures. For example, in ethanol (or ethyl alcohol) the alkyl group is the ethyl group, −CH2CH3.

Alcohols are among the most common organic compounds. The low molecular weight alcohols are soluble, as the size of their alkyl group or aryl group increases, there is a decrease in solubility. intermolecular The boiling points of alcohols are much higher than those of alkanes with similar hydrogen bond CH CH molecular weights. The oxygen atom of the strongly polarized O−H bond of an 2 3 O alcohol pulls electron density away from the hydrogen atom. This polarized CH3CH2 O H hydrogen, which bears a partial positive charge, can form a hydrogen bond with a pair H of nonbonding electrons on another oxygen atom.

Alcohols are used as sweeteners and in making perfumes, are valuable intermediates in the synthesis of other compounds, and are among the most abundantly produced organic chemicals in industry. Perhaps the two best- known alcohols are ethanol and methanol (or methyl alcohol). Ethanol is used in toiletries, pharmaceuticals, and fuels, and it is used to sterilize hospital instruments. It is, moreover, the alcohol in alcoholic beverages. The anesthetic ether is also made from ethanol. Methanol is used as a solvent, as a raw material for the manufacture of formaldehyde and special resin, in special fuels, in antifreeze, and for cleaning metals.

Phenol, any of a family of organic compounds characterized by a hydroxyl (−OH) group attached to a carbon atom that is part of an aromatic ring. Phenols are similar to alcohols but form stronger hydrogen bonds. Thus, they are more soluble in water than are alcohols and have higher boiling points. Phenols occur either as colorless liquids or white solids at room temperature and may be highly toxic and caustic.

Notes:

Be sure to complete the first table on the Report before coming to lab. Draw the structure, identify the alcohol as 1o, 2o, or 3o, and calculate MM.  For the structures, write small so it fits in the required area.  Use the structure to indicate 1o, 2 o, or 3 o.  Calculate molar mass to one digit past the decimal.

For Parts A, B, & C: Seven alcohols listed on the report page (ethanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, 1-hexanol, cyclohexanol & cholesterol) will undergo each test. Each alcohol will be in its own test tube. Be sure to add everything indicated for the test, and mix.

The conclusion for this type of experiment is a summary of the observations and analysis of the data, indicating if the compounds behaved as expected. For example In Part B, did the 1 o alcohols react as expected? It is NOT restating all of the data.

Part A: Solubility of Alcohols in Water Test each alcohol separately. 10 drops ≈ 0.5 mL Procedure for Solubility of ROH: 1. In seven separate test tubes, place 0.5 mL of each alcohol (listed on the table in the report). 2. Add 2 mL of distilled water to each test tube which contains the 0.5 mL ROH. 3. Mix and observe the relative solubility. Ignore any precipitate formed; we are only looking for layers. (layers = not soluble) 4. Record the results for each alcohol as; very soluble, moderately soluble, slightly soluble, or insoluble.

Part B: The Lucas Test The Lucas Test is used identify an alcohol as primary, secondary or tertiary based on reaction rates. The Lucas Reagent is a mixture of zinc chloride and concentrated hydrochloric acid [Caution].

HCl, ZnCl2 R-OH R-Cl + HOH The alkyl Chloride, R-Cl, is insoluble and forms a lower layer or a cloudy solution.

The rate of the reaction depends on whether the alcohol is primary, secondary, or tertiary. Primary alcohols do not react. Secondary alcohols react after 4-5 minutes. Tertiary R R R H + + + + alcohols react immediately. The basis of this rate trend is due to the stability of R C > R C > H C >> H C the intermediate carbocation. The tertiary carbocation is the most stable and the R H H H primary is the least stable.

Procedure for Lucas Test: (Note: Lucas Reagent should be colorless) 1. In seven separate test tubes, place 2 mL of Lucas reagent in each test tube. 2. Add 5 drops of the alcohol to be tested to the test tube with the 2 mL of Lucas reagent. 3. Mix the test tube and note the approximate length of time (immediate, a few minutes, no reaction) it takes the solution to separate into two layers or to become cloudy.

Part C: The Bordwell-Wellman Test Primary alcohols are oxidized to their respective aldehyde. Secondary alcohols are oxidized to their respective 3+ ketone. Tertiary alcohols do not react. The reactant H2CrO4 is orange; if a reaction occurs it is converted to Cr O which is green. R CHOH + 2 H CrO + 10 H+ R C R 3+ 2 2 4 + 2 Cr + 8 H2O orange green

Procedure for Bordwell-Wellman Test: 1. In seven separate test tubes, Place 1 mL of acetone in each test tube. 2. Add 1 drop of the alcohol to be tested to the test tube with the 1 mL of acetone. 3. Add one or two drops of the Bordwell-Wellman reagent to each of the test tubes. 4. Mix the test tube, note your observations (color changes = reaction, no color change = no reaction) 5. To see if there is a color change, you need to prepare a control test using 1 mL acetone and 1 -2 drops Bordwell-Wellman in a test tube and mix. This is the color when no reaction (NR) occurs since acetone is a ketone and will not react.

Part D: The Acidity of Phenols Phenols are stronger acids than alcohols or water. This is a result of the phenoxide ion delocalizing charge into the ring. With alcohols, the negative charge remains located on the oxygen, thus holding on to its proton.

Procedure for Acidity of Phenols: 1. In two separate test tubes, place 0.2 grams of phenol in one test tube & 0.2 grams of p-chlorophenol in a separate test tube. 2. Add 1 mL of distilled water to each test tube. 3. Mix each test tube and note whether the compound dissolves, and note relative solubility. 4. Add 2 mL of 15% sodium hydroxide solution (NaOH), to each test tube. 5. Mix each test tube again and note whether the compound now dissolves. Note relative solubility and the time it takes for the compound to dissolve.

Report: Experiment 19 Name: ______Hydroxyl Group Lab Day ______Date ______

Complete this table before the start of lab for each compound, include it in the prelab write-up in the notebook; draw the structure, identify the alcohol as 1o, 2o, or 3o, and calculate and record molar mass (MM). 1, 1, 1, Compound  Compound  Compound  2 , MM (g/mol) 2 , MM (g/mol) 2 , MM (g/mol) Structure or Structure or Structure or 3 3 3 ethanol 1-butanol 1-hexanol

2-methyl-2-propanol 2-butanol cyclohexanol

cholesterol phenol p-chlorophenol

Record your experimental results and observations: Part A: Part B: Part C:

Solubility in Water The Lucas Test Bordwell-Wellman Test Reaction Compound Solubility in Water Time for Reaction Color after test or NR ethanol

1-butanol

2-butanol

2-methyl-2-propanol

1-hexanol

cyclohexanol

cholesterol

Part D: The Acidity of Phenols Compound Soluble in H2O Soluble with NaOH phenol

p-chlorophenol

Questions: 1. Solubility of Alcohols in Water: In Part A of this experiment, what was the trend in Based on molar masses, which would be less soluble in solubility? water, 1-pentanol or 1-heptanol? Explain. (circle answer)

2. Write an equation for the reaction of 2-butanol with the Lucas reagent.

3. Draw Structures for each and determine if 1o, 2 o or 3 o. How long would you predict for the reaction to take place for the following with the Lucas reagent? Structure 1 o, 2 o or 3 o Time for Reaction 2-methyl-1-propanol

Cyclopentanol

1-methylcyclopentanol

4. Indicate with a yes or no if the pairs of alcohols could be distinguished from each other with the following tests. For each compound: Draw the structure, calculate MM, & determine if it is 1o, 2 o or 3 o. EXAMPLE analysis: if you want to distinguish between a 1 o and 3 o compound, you would want to use a test such as the Bordwell-Wellman since it turns green for 1 o & 2 o and remains orange for 3 o.

Compounds Structure MM in 1o, 2 o Solubility Lucas Bordwell- Acidity or 3 o (consider MM Wellman g/mol and branching) Yes or No Yes or No Yes or No Yes or No 1-propanol and

2-propanol

4-chlorophenol and

4-chlorocyclohexanol

1-butanol and

2-methyl-2-propanol

CHEM 213 ~ Experiment 19: Spectroscopy 1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

MM= MM=

HNMR 6. Draw the structure for the compound. Label each hydrogen type with either numbers or letters. 7. How many different hydrogen types (nonequivalent) are in this compound? 8. Clearly label: a. On the spectrum given identify each signal with a specific hydrogen, and ppm value. b. On the structure you drew, label each hydrogen with the ppm signal value. p-chlorophenol: Number of nonequivalent hydrogens = Cyclohexanol: Number of nonequivalent hydrogens =

List the List the functional functional groups groups

Experiment 20: Synthesis of Alkenes “DRY LAB”

The two simplest methods of synthesis of alkenes are dehydration and dehydrohalogenation. This experiment will prepare an alkene from an acid-catalyzed dehydration of an alcohol. Dehydration follows an E1 mechanism that proceeds with a carbocation intermediate.

Elimination by alcohol dehydration is accomplished by heating in the presence of an acid catalyst such as sulfuric or phosphoric acid. Phosphoric acid is a milder acid and results in higher yields of alkene product and fewer side products than sulfuric acid.

OH O

CH C CH CH H O P OH Reaction: H3C 2 2 3 + alkene mixture + H2O OH CH3 3-methyl-3-pentanol phosphoric acid

Procedure: Reminder: *****Reference Zubrick Lab Text***** Caution: Concentrated phosphoric acid (85 %, 14.7 M) is a strong acid, and is capable of causing serious burns in contact with the skin, or if swallowed.

You will set up a Hickman still set up as in figure 20.1 (left side, with the sand bath, no stir bar and NO FLAMES) add a reflux water condenser to the top for cooling, connect hoses for water flow. You need to use the cap on the side arm.

You will be using 2 separate 5-mL conical vials for this experiment. The vails are different, one will fit into the Hickman still the other will not. Get one of each. The vial (Vial #1) that is to be used in the Hickman still, starting in step 1, will be referred to as Vial #1 , and will be cleaned, dried and reused in step # 6. The second vial (Vial # 2) will start to be used in step 5, this is the vial that will not fit into the Hickman still, but can be capped.

1. Place 1.25 mL of 3-methyl-3-pentanol in a 5-mL conical vial (Vial #1) containing a boiling chip.

2. Add 0.25 mL of 85% phosphoric acid to the alcohol in the reaction vial (Vial #1).

3. Fit the reaction vial (Vial #1) with the Hickman still with condenser, place in a sand bath, and turn on the water to the condenser. You can cover sand bath with foil to keep in heat.

4. Maintain the temperature of the sand to between 100 and 105 oC. Overheating will cause product to be lost, be sure to watch carefully, and do not have the dial on the hot plate set high. Reflux the reaction for about 30 to 55 minutes (start the time of the reflux after boiling starts) or until the collar of the Hickman still is filled with the alkene mixture. The products are very volatile (BP 65 – 68 oC).

5. Add 2 pieces of anhydrous CaCl2 (drying agent) to a separate vial (Vial # 2), then use a Pasteur pipet to transfer the liquid product from the still collar to the vial (Vial # 2) then cap and swirl gently.

6. Clean and dry Vial # 1 that was used in the Hickman still. Record the mass of the clean dry vial (Vial # 1).

7. Use a new Pasteur pipet to transfer the dried liquid (water was removed) from Vial #2 into Vial #1 (the one that was weighed in step 6) and weigh and record mass of Vial #1 with the product in it.

8. Calculate percent yield of product.

Report: Experiment 20 Name: ______Synthesis of Alkenes Lab Day ______Date ______

DRY LAB Data:

Volume 3-methyl-3-pentanol used 1.25 mL

Mass of Clean, Dry Vial _____NA______g

Mass of Vial and Product _____NA______g

Mass of Product Recovered 0.428 g

Questions: (Show calculations in lab notebook)

1. Calculate theoretical yield & percent yield of product, identify carbocation. Using the density of 3-methyl-3- Calculate percent yield of Draw the carbocation that pentanol ______g/mL, product. (Since all isomers have generates the alkenes in this Fill in same MM you will be calculating experiment. calculate theoretical yield of percent yield of all alkenes product in mass. formed).

g %

2. Draw and name the 2 alkene isomer products that are formed in this reaction. (Disregard E-Z isomers)

______

3. Predict which alkene should be the major product: ______Explain:

4. How does a drying agent work? Why was it used in this experiment?

CHEM 213 ~ Experiment 20: Spectroscopy 1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

MM=

(Z)-3-methyl-2-pentene: Number of nonequivalent carbons = (E)-3-methyl-2-pentene: Number of nonequivalent carbons =

IR 6. List the functional groups and signals that can be identified in this IR spectrum for the compound. 7. On the IR spectrum, clearly label the signals for the major functional groups, identify the fingerprint region. (Z)-3-methyl-2-pentene (E)-3-methyl-2-pentene

List the List the functional functional groups groups

3-methyl-2-pentene

List the functional groups

Experiment 21: Reduction of a Ketone to Form a Diol

Preparation of alcohols in the laboratory is often accomplished by either hydration of alkenes or by the reduction of aldehydes or ketones. In this experiment, the mild reducing agent sodium borohydride will selectively reduce benzil, a diketone to hydrobenzoin, a diol. This reduction reaction requires involves the transfer of hydride from borohydride ion to the carbonyl carbon and protonation of the resulting alkoxide by the solvent ethanol or methanol. The first equivalent of hydride forms α-hydroxyketone (benzoin); the second equivalent of hydride forms the diol (hydrobenzoin). The addition of hydride to the top or bottom face of benzoin produces different stereoisomers. The product can be characterized from melting point; meso-hydrobenzoin has a reported MP at 137 oC; and (±)-hydrobenzoin at 120 oC.

O O HO OH

Reaction: ethanol + NaBH 4 2 2

benzil hydrobenzoin Procedure:

Start boiling water on a hot plate at beginning of lab to have ready for step 5.

1. Prepare a solution of benzil by adding 0.200 g benzil and 2 mL 95% ethanol to a 25-mL Erlenmeyer flask and swirl to mix.

2. Add 0.075 g NaBH4 (you may need to break up NaBH4 with stirring rod to get a greater surface area) to the solution of benzil, let stand 10 minutes with occasional swirling. After adding NaBH4, a chunky white precipitate will form, and yellow will go away as benzil is reduced.

3. Slowly add 2 mL distilled water (foaming may occur), and then heat the solution to boiling. The solution should be clear and colorless.

4. If a precipitate is present, then transfer solution to a clean Erlenmeyer flask using a Pasteur pipet. If no precipitate, then keep it in the same flask.

5. Add an additional 2 mL of hot distilled water to the hot solution.

6. Allow the solution to crystallize undisturbed to form thin, shiny plates.

7. Cool in an ice bath. Obtain mass of filter paper, then vacuum filter the crystals using a Buchner funnel. Wash the crystals with a minimum amount of cold water.

8. Allow crystals to completely dry, weigh, and determine purity using melting point range and calculate percent yield of product.

Report: Experiment 21 Name: ______Reduction of a Ketone to form a Diol Lab Day ______Date ______

Data: Mass of Mass of Mass of Filter Paper Melting Point Range Mass Benzil Mass NaBH4 Product Filter Paper and Dried of Product Recovered Product

o g g g g g C

Questions & Calculations: (Show all calculations in lab notebook)

2. Based on your melting point results, what is the name of the major product formed in this reaction?

2. Complete the table Molar Mass (g/mol) Mass Used (g) Initial Mole (mol) using your data Benzil

NaBH4

3. Calculate theoretical yield & percent yield of product using the limiting reagent. (Note mole ratio) Which reactant is the limiting Theoretical Yield Product Percent Yield Product reagent?

g %

4. Give all three stereoisomer structures produced by the reduction of benzil to hydrobenzoin as Fisher projections, following the labeled stereogenic centers. Ph represents the phenyl group.

Ph Ph Ph

(S,S) (R,R) (S,R) meso

CHEM 213 ~ Experiment 21: Spectroscopy 1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

MM=

HNMR 6. Draw the structure for the compound. Label each hydrogen type with either numbers or letters. 7. How many different hydrogen types are in the compound? 8. Clearly label: a. On the spectrum given identify each signal with a specific hydrogen, and ppm value. b. On the structure you drew, label each hydrogen with the ppm signal value. (+/-)-HYDROBENZOIN: Number of nonequivalent hydrogens =

List the functional groups

Experiment 22: Mixed Aldol Condensation: Preparation of a Ketone

This topic is covered in chapter 23 of McMurry Text One of the more important properties of aldehydes and ketones is the α-hydrogens are relatively acidic. The aldol reaction is the carbonyl condensation reaction of an aldehyde or ketone to give a β-hydroxy carbonyl compound. A carbon-carbon bond is formed between the α -carbon of one molecule and the carbonyl carbon of another. A mixed aldol condensation is a reaction between two different aldehydes or ketones, at least one of the compounds should be an aldehyde. This condensation is generally practical only if one of the components has no acidic α-hydrogens or else up to four products can be formed.

Dehydration of the aldol products to give α, β -unsaturated carbonyl compounds is easily accomplished upon heating. The first step is the deprotonation of an α-hydrogen by a strong base to form a resonance stabilized enolate ion. The enolate ion is very reactive and will add to the carbonyl of an aldehyde. The initial product is α, β -hydroxyaldehyde, which can undergo base-catalyzed elimination upon heating to yield an α, β-unsaturated aldehyde.

Reactions with strong bases can convert a ketone molecule partially to an anion. In this experiment, you will investigate the aldol condensation and its application of β-hydroxyaldehydes and ketones by performing a mixed aldol condensation, through synthesis of an α, β -unsaturated ketone. O

O O Reaction: KOH 2 + 2 H O + bright yellow 2 cinnamaldehyde acetone dicinnamalacetone 3-phenylpropenal 1,9-diphenyl-1,3,6,8-nonatetraen-5-one Procedure:

1. Place 0.4 mL cinnamaldehyde and 2.5 mL 95% ethanol in a 25-mL Erlenmeyer flask.

2. Add 1.5 mL 2 M KOH, swirl to mix. The solution should be a pale yellow.

3. Add 0.11 mL acetone, swirl vigorously to mix, and then let the flask stand undisturbed for several minutes. The product will precipitate from solution forming bright yellow crystals.

4. Cool in an ice bath for an additional 15 minutes to ensure complete crystallization.

5. Vacuum filter the crystals using a Hirsch funnel. Wash the crystals with several small portions of ice-cold 95% ethanol.

6. Recrystallize the product from 2-propanol or 95% ethanol (obtain mass of filter paper).

7. Allow crystals to completely dry, weigh, and determine purity using melting point range and calculate percent yield of product.

Report: Experiment 22 Name: ______Mixed Aldol Condensation: Lab Day ______Date ______Preparation of a Ketone

Data: Mass of Filter Paper and Mass of Product Melting Point Range of Mass of Filter Paper Dried Product Recovered Product

o g g g C

Questions and Calculations: (Show all calculations in lab notebook)

1. Calculate mass and initial moles for each reactant. Reagent Volume (mL) Density (g/mL) Mass (g) Mole (mol)

Cinnamaldehyde

Acetone

2. Calculate theoretical yield & percent yield of product using the limiting reagent. (Note mole ratio)

Which reactant is the limiting Theoretical Yield Product Percent Yield Product reagent?

g %

(You may reference chapter 23 of McMurry text for questions 3 & 4) 3. What enone product would 3-methylbutanal cyclohexanone you expect from the aldol condensation of the following? Use line structures for your answers. (Note: This is not a mixed aldol question, treat each compound independently)

4. Write all the possible aldol products from the two reactants propanal & acetaldehyde. Use line structures for your answers. (Note: This is a mixed aldol reaction, you will have 4 products)

CHEM 213 ~ Experiment 22: Spectroscopy 1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

MM=

Dicinnamalacetone: Number of nonequivalent carbons =

Dicinnamalacetone: Number of nonequivalent hydrogens =

Dicinnamalacetone:

List the functional groups

Experiment 23: Aldehyde and Ketone Reactions

Part A: Oxidation Reactions

O Strong [O] O Aldehydes and ketones react differently towards oxidizing agents. R C H R C OH Aldehydes are easily oxidized to acids with the same number of carbon atoms. Ketones basically do not undergo oxidation, but rarely may be oxidized only under stronger reagents and higher temperatures. (The oxidation to an acid requires the breaking of a carbon-carbon bond). Aldehydes and ketones can be distinguished based on the fact that they oxidize under different conditions.

Tollens’ Silver Mirror Test

O Ag O, NH OH O 2 4 C C + Ag(s) R OH R H H2O, ethanol

Tollens’ reagent is an ammonia solution of silver ion prepared by dissolving silver oxide in ammonia. The Tollens’ reagent is reduced to metallic silver by aldehydes. The aldehyde is oxidized to the corresponding acid as the Tollens’ reagent is reduced. Ketones do not usually react with Tollens’ reagent. Tollens Reagent test is a qualitative test for an aldehyde, the observation of a silver mirror indicates a positive test.

Procedure: Smelly lab, turn on hoods Preparation of Tollens’ Reagent 1. Clean a medium test tube thoroughly with soap and water. Rinse it with distilled water. Place 2 mL of 5% silver nitrate solution in the clean test tube. 2. Add 0.5 mL of 5% NaOH and mix thoroughly. 3. While stirring vigorously, add enough 2% ammonium hydroxide to just dissolve precipitate. Do not add more ammonium hydroxide than required, or the test will not work. (If all of the precipitate does not dissolve after the test tube is half full, DO NOT add any more ammonium hydroxide). 4. Let the undissolved precipitate settle and decant off the clear liquid for use. Don’t transfer the precipitate. 5. Divide the Tollens’ reagent equally among five clean test tubes. 6. Add 2-3 drops of the following carbonyl compounds to one of the 5 test tubes that contain the Tollens’ reagent: acetone, 3-pentanone, formaldehyde solution*, 16% acetaldehyde, and Benzaldehyde (use 7- 10 drops) * (This was prepared by adding 5 drops of formalin to 5 mL distilled water, already made for students), 7. Shake each mixture, and allow standing for 10 minutes. 8. If no reaction occurs, place the test tube in a beaker of water, which is at 35-50C for 5 minutes. 9. Record your observations. 10. Clean silver from test tubes with a few drops of dilute nitric acid.

Part B: Addition Reactions MM 104 g/mol OH MM 162 g/mol O - + + + HOSO Na R CH SO- Na R C H 2 3 sodium bisulfite bisulfite addition compoud Bisulfite Addition compounds. Aldehydes and some ketones react with saturated aqueous sodium bisulfite to form white crystalline addition products. The nucleophile is the bisulfite ion. Copyright © 2018 K. Boebinger 33 Spring 2018 [CHEM 213 OCHEM LABORATORY EXPERIMENTS]

Procedure: 1. Pipet 5 mL of 20% aqueous sodium bisulfite into a 50-mL Erlenmeyer flask. 2. Cool the solution in an ice bath for 5 – 7 minutes. 3. Add 5 mL acetone using a disposable pipet. If precipitate doesn’t form after 10 minutes, then cool mixture again and add a little more acetone (may need 10 – 20 mL more acetone). 4. Filter the adduct (addition product) with the vacuum using a Büchner funnel (Fig. 13.5). Be sure to weigh the filter paper and cool the funnel by placing it in an ice bath before you filter. You may wash the PPT with minimal amounts of cold acetone. 5. Record color and weight of product.

Part C: Reactions of Enolate Anions

Enolate anions can act as nucleophiles in many reactions. Enolate anions react rapidly with halogens to give - halocarbonyl compounds. For iodine the reaction is:

O O - - R C C + I I R C C I + I

Compounds are treated with iodine and a base, iodoform (CHI3) deposits as a yellow crystalline compound with a typical medicinal odor.

Procedure: 1. Add 3 mL of 5% NaOH to five separate test tubes. 2. Add five drops of each of the following carbonyl compounds to one test tube containing the NaOH; acetone, 2-propanol, 2-pentanone, 3-pentanone, and formaldehyde solution 3. Add iodine solution and shake it until the color of the iodine barely persists. This may take up to 10 mL of solution for 3-pentanone. ( Note: Your small test tube has a volume of about 10 mL) 4. The yellow precipitate of iodoform should be apparent if the reaction occurs. Record any color changes and the medicinal odor.

Part D: The Aldol Condensation: Enolate anions can add to carbonyl groups since they are nucleophiles. When acetaldehyde is treated with dilute base, it condenses with itself to give Aldol. Upon heating, the Aldol loses water, giving the unsaturated aldehyde, crotonaldehyde.

- O 1. OH O H C CH CH C H + HOH 2 H3C C H 2. heat 3 acetaldehyde crotonaldehyde Procedure:

1. Add 1 mL of 5% sodium hydroxide to 3 mL of 16% aqueous acetaldehyde in a small beaker. Shake well. Note the odor of the unreacted aldehyde. 2. Boil the mixture for three minutes. Cautiously note the pungent odor of the product. 3. Record observations.

Report: Experiment 23 Name: ______Aldehyde and Ketone Reactions Lab Day ______Date ______

Part A: Tollens’ Silver Mirror Test

Observation or Reaction or Compound Write a balanced reaction for all tests. color NR

Benzaldehyde

Acetone

3-pentanone

Formaldehyde

Acetaldehyde

Part B: Addition Reactions Write Balanced Reaction

DATA: Mass of Product & Filter Paper Mass of Filter Paper Mass of Product

g g g Calculations: Show all calculations in lab notebook 1. Calculate mass of 5 2. Calculate grams 3. Convert to Moles 4. Calculate 5. Calculate Percent mL of 20% aqueous Sodium Bisulfite in Sodium Bisulfite Theoretical Mass of Yield Sodium Bisulfite 20% solution Product solution (D = 1.14g/mL) (Multiply mass solution by 0.20)

g g mol g %

Part C: Reactions of Enolate Anions

Observation/ Reaction Write a balanced reaction for all tests. Compound color/ppt or NR

Acetone

2-propanol

2-pentanone

3-pentanone

Formaldehyde

Part D: Aldol Condensation

Write balanced reaction from experiment.

Observations and description of precipitate:

CHEM 213 Experiment 23 Spectroscopy Identify the unknown compounds. These where used in this experiment.

Compound 1: Identify ______

Compound 2: Identify ______

Compound 3: Identify ______

Experiment 24: Isolation of Milk Protein water from casein, casein may stay wet and take Proteins are made up of covalently bonded amino days to dry, so make the call when to weigh acids. The function of a protein and structure is casein. influenced by the identity and sequence of the amino acids. If the protein is tightly coiled and 7. Weigh and record mass of product. Calculate folded into a somewhat spherical shape, it is called percent casein isolated. a globular protein. In this experiment, you will isolate the milk protein casein which makes up 79.5 Casein Analysis: (You will not use your casein, % of all milk proteins from the whey solution. use the dried casein provided)

Milk contains proteins, vitamins, minerals, Prepare casein solution: Crush the dried casein carbohydrates, and fats, and is considered one of in a mortar and pestle so that the granules are the most nutritionally complete foods. Milk is an no bigger than sand grains. Prepare about 6 mL emulsion, not a solution, of lipids in water, casein solution. To make a casein solution for stabilized by phospholipids and proteins bound to testing, mix a micro-spatula full of finely crushed the surface of the fat globules. Milk is homogenized casein powder per 1 ml of water. Perform the to break up the fat globules and distribute them tests as indicated. evenly, and pasteurized to kill disease causing bacteria. Fat content varies depending on the type Characterization Tests: Identification of milk product; low fat (skim) milk 1%, whole milk of Amino Acids 3.25 %, half and half 12 %, whipping cream 35%,

and butter 80 – 82%. Part A

Biuret Test: Confirms presence of a protein.

Biuret reagent is a light blue solution which Procedure to Isolate Casein: turns purple when mixed with a solution containing protein. The purple color is formed 1. Place 10 g of powdered nonfat dry milk (record when copper ions in the Biuret reagent react mass) into a 150-mL beaker. Add 40 mL warm with the peptide bonds of the polypeptide water and stir to dissolve. chains to form a complex.

2. Gently warm the solution on a hot plate to 40 – 45 Procedure for Biuret Test: o o C. Do not let the temperature exceed 50 C. 1. Thoroughly mix 1 mL of 10% NaOH solution with 1 mL of casein solution in a medium test 3. With constant stirring, add 10% acetic acid drop tube. O O O wise until the liquid changes from milky white to clear, until no more casein precipitates. NH R R HN NH R OH- , Cu2+ Cu 2+ blue 4. Continue stirring until the casein forms a large NH O O HN NH O mass. Use a stirring rod to transfer the mass to a

prepared Buchner funnel with a reweighed filter pink or violet paper, and vacuum flask to filter. 2. Add one drop of 2% copper sulfate. Mix 5. Wash the casein with cold ethanol, then cold thoroughly and note if a pink or violet color diethyl ether to remove impurities. develops. If not, add additional drops (up to 10) of copper sulfate, mixing after each addition. The 6. To help remove excess liquid, place a second filter formation of a pink or violet-blue color constitutes a paper on top of precipitate, and gently press with positive test. a beaker. Continue suctioning to remove excess

Part B Xanthoproteic Acid Test: This test will determine if residues of the amino acids tyrosine or tryptophan are present. The solution to be tested is treated with concentrated nitric acid, which will nitrate the Part C benzene rings of those residues. The nitrated Sulfur Test: The presence of sulfur-containing aromatic rings are yellow in color and are called amino acids such as cysteine or methionine can Xanthoproteic acids (Xantho, = yellow, Greek). If be determined by converting the sulfur to an base is added, the color of the precipitate becomes inorganic sulfide through cleavage by base. more intense and the color will shift more to When the resulting solution is combined with orange. lead acetate, a dark brown to black precipitate of lead sulfide results. 2+ NaOH Pb Procedure for Xanthoproteic Acid Test: sulfur-containing protein S2 - PbS

O + O + N - N - O O Procedure for Sulfur Test:

HNO3 NaOH OH OH ONa 1. Add 2 mL of 10% aqueous sodium hydroxide yellow orange-yellow along with 5 drops of 10% lead acetate solution to 1 mL of casein solution in a 1. Add 1 mL of concentrated nitric acid to 2 mL of medium test tube. the casein solution in a medium test tube. Note the appearance of any heavy white precipitate. 2. Stopper the test tube and shake to mix.

2. Warm the solution carefully in a hot water bath 3. Remove the stopper and heat in a hot (beaker of water on a hot plate), noting any water (boiling) bath for 5 minutes. change to a yellow-colored solution. 4. Cool the test tube in a stream of water and 3. Cool the test tube in a stream of cold water record the results. The presence of a dark and carefully add 10% NaOH with gentle brown to black precipitate indicates the agitation. Note if the color of precipitate presence of sulfur containing amino acids. deepens to orange, which would be a positive test.

Report: Experiment 24 Name: ______Isolation of Milk Protein Lab Day ______Date ______

Data for Isolation of Casein: Mass Nonfat Mass Filter Mass Filter Mass Casein Calculate the percent Casein isolated (Show Dry Milk Paper Paper & calculation in Lab Notebook) Casein

g g g g %

Results for Characterization (Qualitative) Tests for Amino Acids: Part Observations and Results for A Biuret test:

Part Observations and Results for B Xanthoproteic Acid test:

Part Observations and Results for C Sulfur test:

Analysis: Based on the results from the Xanthoproteic Acid test, what amino acids may be present in casein? Give names and structures.

Based on the results from the Sulfur test, what amino acids may be present in casein? Give names and structures.

CHEM 213 ~ Experiment 24: Spectroscopy 1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

2. On each of the spectra provided, Identify: Parent Peak, Base Peak, fragment losses with proposed fragments, and fragment signals with proposed structures in the MS for the compound.

L-cysteine: C3H7NO2S Structure:

MM=

L-cysteine: C3H7NO2S: Number of nonequivalent carbons =

L-cysteine: C3H7NO2S: Number of nonequivalent hydrogens =

L-cysteine: C3H7NO2S:

List the functional groups

Experiment 25: Soaps and Detergents

Saponification is the treatment of an ester with a base to produce the acid and the alcohol from which the ester is made. Saponification is used to describe this process because it is how soap is made.

In this experiment, soap is made by boiling oil (a triester of glycerol) in a mixture of alcohol and aqueous sodium hydroxide. The products are soap (the sodium salts of the long chain acids that are from the oil) and glycerol (the alcohol part of the oil.) Salting the soap with a saturated sodium chloride and washing the soap with cold water remove excess sodium hydroxide and glycerol.

Fats and oils are glycerides, triesters of glycerol with long chain carboxylic acids. The R group can vary in length and saturation. The most common acids are in fats and oils with carbon chains of 12 – 18 atoms. If the R groups of the glycerides are nearly saturated or saturated, the solids are called fats. Highly unsaturated glycerides are oils; double bonds in the R group lower the melting point. Vegetable oils can be converted to fats such as shortening or margarine by hydrogenating some of the double bonds. The long carbon chain in the R groups of fats and oils give them hydrocarbon like properties. Fats and oils are soluble in nonpolar solvents.

Detergent properties: The most important structural feature of a soap molecule is that one end is polar and ionic and the longer carbon chain is nonpolar. This allows soap to dissolve in both polar and nonpolar solvents. Synthetic detergents (syndet) mimic the structural properties of ordinary soaps.

Soap Ionic Detergents Nonionic Detergent Cationic (Invert) Detergent - + O CH OH ROSO3 Na 2 CH3 O + - R C O CH2C CH2OH R N CH3 Cl - + + R C O Na R SO -Na 3 CH OH 2 CH3

Water Hardness: Sodium and potassium salts of ordinary soaps are water soluble. Calcium, magnesium, and iron salts are not. Calcium, magnesium and iron are present in hard water and they will form a precipitate with ordinary soap, known as soap scum. This removes the soap from the solution and O O - 2+ - decreases the effectiveness as a detergent. Most syndets do not form insoluble calcium or R C O Ca O C R magnesium salts, therefore they function almost as well in both soft and hard water. Soap Scum

Part A: Preparation of Soap from Fat Reflux set-up 1. Assemble a reflux apparatus using a 100-mL round bottom flask. 2. Place 10 grams of shortening (record mass) in the flask. 3. Add to it a solution of 10-g NaOH (record mass) in 35-mL of a 1:1 mixture of ethanol and water. Add 3 or 4 boiling chips. 4. Attach a condenser, water in at the bottom and out of the top. Water should circulate at a slow rate. 5. Gently reflux the mixture over a sand bath for 40 – 45 minutes. (Do not start timing until mixture is recondensing). A homogeneous mixture should form. 6. During the reflux, occasionally loosen the condenser clamp and swirl the flask to wash the materials off of the walls of the flask and into the reagent mixture. DO NOT DISCONNECT during this step. 7. While the saponification is in progress, prepare a concentrated salt solution by dissolving 50-g of salt in 150- mL of water in a 600-mL beaker. 8. When the saponification is complete, remove the flask from the heat source.

9. Using a thermal mitten to hold the hot flask, pour the reaction mixture quickly into the saturated salt solution. DO NOT GET THIS SOLUTION ON YOU. 10. Stir the mixture for several minutes. Stir in scent when not too hot or cold. 11. Collect the precipitated soap on a Buchner funnel. Weigh filter paper. 12. Wash the soap twice with 10-mL of ice-cold distilled water. 13. Draw air through the soap for several minutes to dry it. Weigh and record mass of product. 14. Save 1 gram of your product for Part B. The remaining soap may be put into the mold. 15. Calculate percent yield of soap produced. O O H C OH H2C O C R 2 Na O C R Reaction to prepare soap: O + 3 NaOH O

Note mole ratio HC O C R' HC OH + Na O C R' fat:soap is 1:3 O O H C OH H2C O C R" 2 Na O C R" Fats or Oils Glycerol Soaps

C54H110O6 C3H8O3 C18H35O2Na MM 854 g/mol MM 92 g/mol MM 306 g/mol

Part B: Soap & Detergent Properties

1. Bring about 150-mL of distilled water in a beaker to a boil using a hot plate. 2. Carefully pour about 50-mL of the hot water into a separate beaker and dissolve about 1-g of your soap with stirring. 3. Use the beaker that was used to boil the water, and remove just enough water to have 50-mL hot water remain and dissolve about 1-g of synthetic detergent (syndet) such as Tide®, Joy®, or All®. 4. You will use these solutions for both Part B I & Part B II of this experiment.

Part B I: Solubility of Soap and Detergents 1. Place four drops of mineral oil in each of three clean medium test tubes. 2. Add 5-mL of distilled water to test tube 1. 3. Add 5-mL of your soap solution to test tube 2. 4. Add 5-mL of syndet solution to test tube 3. 5. Shake each test tube briefly and observe how well the oil is emulsified. 6. Record your results and observations.

Part B II: Hard Water tests: If a precipitate is formed, then that is a positive test for hard water. Indicate if the following tests form a precipitate or are soluble. 1. Place 5-mL of your soap solution in each of three clean test tubes. 2. Add 2-mL of 1% CaCl2 to test tube 1. 3. Add 2-mL of 1% MgCl2 to test tube 2. 4. Add 2-mL of 1% FeCl3 to test tube 3. 5. Place 5-mL of your syndet solution in each of three clean test tubes. 6. Add 2-mL of 1% CaCl2 to test tube 1. 7. Add 2-mL of 1% MgCl2 to test tube 2. 8. Add 2-mL of 1% FeCl3 to test tube 3. 9. Record your results and observations.

Report: Experiment 25 Name: ______Soaps and Detergents Lab Day ______Date ______

Part A: Observations and Results for Preparation of Soap

Brief Description of Soap: ______

Mass Filter Paper and Mass of Shortening Mass of NaOH Mass Filter Paper Mass of Soap Formed Soap Formed

g g g g g

Calculations: (Show all calculations in lab notebook) Theoretical Mass Product Initial Moles Lard Initial Moles NaOH (Keep in mind mole ratio and Percent Yield Soap limiting reagents)

mol mol g %

Part B: Soap & Detergent Properties Part B I: Solubility of Soaps and Part B II: Hard Water Tests Detergents Soluble, Slightly Soluble, Soap Detergent or Insoluble Indicate if PPT formed Indicate if PPT formed Test Tube 1 Test Tube 1 CaCl2 Test Tube 2 Test Tube 2 MgCl2 Test Tube 3 Test Tube 3 FeCl3

Analysis of Part B II Results Which of the reagents (metals) reacted with soap and Which of the reagents (metals) reacted with detergent and formed hard water? (Circle all that apply) formed hard water? (Circle all that apply)

Ca2+ Mg2+ Fe3+ Ca2+ Mg2+ Fe3+

CHEM 213 ~ Experiment 25: Spectroscopy 1. For each compound: Draw the structure for the compound and indicate the molecular mass of the compound: MS

2. On each of the spectra provided, Identify: Parent Peak, Base Peak, fragment losses with proposed fragments, and fragment signals with proposed structures in the MS for the compound.

Glycerol C3H8O3 Structure:

MM=

Glycerol C3H8O3: Number of nonequivalent carbons =

Glycerol C3H8O3: Number of nonequivalent hydrogens =

Glycerol C3H8O3:

List the functional groups

APPLICATION PROJECT (60 PTS) You will do research and present a poster to the class. Key Due Dates and Times: Topic Approved by Instructor: Monday March 26th (each day late -5 points) You must post your organic compound on the Discussion Board in Blackboard, each student must have a different compound) Poster turned into lab room: Before Monday May 7h @ 7:20 am (Early posters encouraged, do not be late to lecture) th Poster Session: (Attendance mandatory) Tuesday May 8 @ 7:30 am

LATE PROJECTS WILL NOT BE ACCEPTED. PLAN AHEAD.

Poster must be free-standing & only information on poster will be considered

Topic: It must relate to organic chemistry, you may A) Choose a specific compound or B) Choose a compound(s) that relates to a scientific or medical field you are interested in. (Must be presented from an organic chemistry point of view).

1) Research: Find 3 sources of current information (2009 or later) from a scientific source; journals, books (textbook OK for one resource), internet sources (only if from a government or educational source). Dictionary sites not acceptable. Prepare a bibliography for these materials. Describe the credentials of the authors. 2) Application: Apply the topics you have been learning about in CHEM 212 and 213 to your research topic. (Minimum 6 applications). 3) Illustrate: Include molecular structures, chemical reactions, synthesis reactions, graphs, or other diagrams relevant to understanding your topic. Build a model. Make sure these are clearly labeled! 4) Spectroscopy: present example(s) and explain spectra of the molecule. 5) Explain: Write an explanation of the key chemical concepts behind your research topic. 6) Importance: What is the importance of this application of organic chemistry?

Abstract: Prepare an abstract of your research topic. Include this on the poster, clearly labeled. The purpose of an abstract is to allow the reader to judge whether it would serve his or her purposes to read the entire report. A good abstract is a concise (100 to 200 words, one paragraph) summary of the purpose of the report, the data presented, and the author's major conclusions.

Poster Session: Poster Session will be Friday May 12th. The posters will be presented in lab, and each student will have an opportunity to see all of the presentations. Each student will evaluate two presentations as part of their grade. You will be required to be available to answer questions that may come up from the instructor or students during the poster session. You must attend poster session for credit; absence will result in a 50% point penalty for poster, plus loss of evaluation points. Sample of what is required:

Rating: 1=poor Comments/Notes Applications Project Evaluation Form 4=best Are there: 3 sources of current reliable information, Research bibliography, credentials of the authors? Are there a minimum of 6 CHEM 212, 213 Application applications? Are these illustrated and labeled clearly: molecular Illustrate structures, chemical reactions, synthesis reactions, graphs, or other diagrams, and the model? Are there relevant spectra presented and clearly Spectroscopy labeled and explained? Explain Are key concepts explained clearly? Is the importance of this application of organic Importance chemistry clearly explained?