CHEM 213CHEM 213Organic LaboratoryOrganic Laboratory

CHEM 213 – Organic LabCHEM 213 – Organic LabImportant Information:

Lab SectionLab Section 001 T (2:30 – 5:00 PM)001 T (2:30 – 5:00 PM) 002 W (1:25 – 3:55 PM)002 W (1:25 – 3:55 PM)003 R (9:30 AM – 12:00 PM)003 R (9:30 AM – 12:00 PM)

004 R (2:30 – 5:00 PM)004 R (2:30 – 5:00 PM)

InstructorInstructor Dr. Martin KociolekDr. Martin Kociolek Mrs. Tracy HalmiMrs. Tracy Halmi Dr. Michael JustikDr. Michael Justik

OfficeOffice 37 Hammermill37 Hammermill 35 Hammermill35 Hammermill 32 Hammermill32 Hammermill

EmailEmail mgk5@psu.edumgk5@psu.edu tracy@psu.edutracy@psu.edu mwj10@psu.edumwj10@psu.edu

PhonePhone 898-6411898-6411 898-6045898-6045 898-6412898-6412

Web PageWeb Page chemistry.bd.psu.edu/kociolek/chemistry.bd.psu.edu/kociolek/ chemistry.bd.psu.edu/halmi/chemistry.bd.psu.edu/halmi/ chemistry.bd.psu.edu/justik/chemistry.bd.psu.edu/justik/

Office HrsOffice Hrs T 9:30 –11:00 AMT 9:30 –11:00 AMW 1:30 – 3:00 PMW 1:30 – 3:00 PM

M 1:25 – 3:15 PMM 1:25 – 3:15 PMW 9:30 – 10:45 AMW 9:30 – 10:45 AMF 1:25 – 2:15 PM & by apptF 1:25 – 2:15 PM & by appt

M 8:00 –11:00 AMM 8:00 –11:00 AM

Recitation: All students will attend mandatory lab recitation on Mondays 3:35 PM. Recitation will NOT meet every week, see attached schedule for recitation dates.

Week ofWeek of Recitation ReadingsRecitation Readings EXPERIMENTEXPERIMENTASSIGNMENTASSIGNMENT

DUE DATESDUE DATES

8/27*8/27*TechniquesTechniques

1, 2, & 31, 2, & 3 Check-inCheck-in Safety QuizSafety Quiz

9/39/3TechniquesTechniques6, 9, & 106, 9, & 10

Experiment #1Experiment #1::Purification of Solid Organic CompoundsPurification of Solid Organic Compounds --

9/10*9/10*TechniquesTechniques

11, 13, 16, & 1811, 13, 16, & 18Experiment #2Experiment #2::

Purification of Liquids by DistillationPurification of Liquids by Distillation --

9/179/17 -- Experiment #2Experiment #2: continued: continued Exp #1 Short ReportExp #1 Short Report

9/24*9/24* Technique 8 & 11.7Technique 8 & 11.7 Experiment #3Experiment #3: Steam Distillation: Steam Distillation --

10/110/1 -- Experiment #3Experiment #3: continued: continuedExp #2 Short ReportExp #2 Short Report

& Notebook& Notebook

10/8*10/8* HandoutHandout Experiment #4Experiment #4: Acid/Base Extraction: Acid/Base Extraction --

10/1510/15 -- Experiment #4Experiment #4: continued: continued Exp #3 Short ReportExp #3 Short Report

10/22*10/22* Technique 15Technique 15Experiment #5Experiment #5::

Thin-Layer ChromatographyThin-Layer Chromatography --

10/2910/29 -- Experiment #5Experiment #5: continued: continued Exp #4 Full ReportExp #4 Full Report

11/5*11/5* Technique 17Technique 17 Experiment #6Experiment #6: Benzoylation of Ferrocene: Benzoylation of Ferrocene --

11/1211/12 -- Experiment #6Experiment #6 continued continued Exp #5 Full ReportExp #5 Full Report

11/1911/19 -- Thanksgiving Week – No LabThanksgiving Week – No Lab --

11/26*11/26* HandoutHandout Experiment #7Experiment #7: Synthetic Puzzle: Synthetic Puzzle Exp #6 Full ReportExp #6 Full Report

12/3*12/3* Final examFinal exam Experiment #7Experiment #7: continued: continued --

12/1012/10 -- No LabNo LabExp #7 Full ReportExp #7 Full Report

& Notebook& Notebook

* NOTE: Lab recitation will only meet on these Mondays.

Laboratory Schedule

Required Materials:Required Materials:

Text:Text: Techniques in Organic Chemistry, 2nd editionTechniques in Organic Chemistry, 2nd editionJerry R. Mohrig et al, W. H. Freeman and Company, Jerry R. Mohrig et al, W. H. Freeman and Company,

20062006

HandoutsHandouts:: Downloaded from instructor’s web site prior to recitationDownloaded from instructor’s web site prior to recitationfor each new experimentfor each new experiment

Notebook:Notebook: A A boundbound notebook is required notebook is required unacceptable - spiral or three-ring bound notebooksunacceptable - spiral or three-ring bound notebooks most convenient - composition notebookmost convenient - composition notebook

Goggles:Goggles: Any goggles or safety glasses with side-shields Any goggles or safety glasses with side-shields

Software:Software: ChemDraw @ https://downloads.its.psu.edu/ ChemDraw @ https://downloads.its.psu.edu/

Assignments:Assignments: Notebook (35 pts) Notebook (35 pts)

PreLabPreLab

Quizzes (50 pts)Quizzes (50 pts) recitation includes a short (10 pt) quiz on the readings recitation includes a short (10 pt) quiz on the readings six quizzes - no make-up quizzes – but one quiz may be droppedsix quizzes - no make-up quizzes – but one quiz may be dropped

Lab Reports (275 pts): Lab Reports (275 pts): First 3 experiments a short report (25 pts each), emphasizing a particular sectionFirst 3 experiments a short report (25 pts each), emphasizing a particular section Final 4 experiments require a full report (50 pts each) Final 4 experiments require a full report (50 pts each) Late reports will be penalized at Late reports will be penalized at two points per daytwo points per day up until they are one week late when up until they are one week late when

they will not longer be accepted. they will not longer be accepted.

Final Exam (75 pts):Final Exam (75 pts): A comprehensive final exam will be given during the recitation. (see schedule)A comprehensive final exam will be given during the recitation. (see schedule)

General Lab Courtesy:General Lab Courtesy: Failure to collaborate, cooperate and abide by the safety rules will result in an automatic Failure to collaborate, cooperate and abide by the safety rules will result in an automatic

deduction of points from that lab, at the discretion of the instructor. Students who do not deduction of points from that lab, at the discretion of the instructor. Students who do not checkout their desk equipment will be charged a $25 checkout fee.checkout their desk equipment will be charged a $25 checkout fee.

Grades:Grades:

Notebook 35 pts

Quizzes (5 x 10 pts) 50 pts

Lab Reports (3 x 25 pts, 4 x 50 pts) 275 pts

Final Exam 75 pts

Total 435 pts

The minimum grade you will receive :A (100-93%), A- (92-90 %), B+ (89-87%), B (86-83%), B- (82-80%), C+(79-75%), C (74-70), D (69-60%), F (<60%).

Notes:Notes:

Academic Integrity: Academic Integrity: It is expected that each student will do his/her own It is expected that each student will do his/her own work on all assignments including quizzes and laboratory reports. work on all assignments including quizzes and laboratory reports.

This includes but is not limited to …This includes but is not limited to … stealing, purchasing or copying quizzes and/or laboratory reports from present stealing, purchasing or copying quizzes and/or laboratory reports from present

or previous students.or previous students. even the possession of other student’s notebook, laboratory reports, or even the possession of other student’s notebook, laboratory reports, or

quizzes constitutes a violation of the academic integrity polity at Penn State. quizzes constitutes a violation of the academic integrity polity at Penn State.

For more information see the Academic Integrity & Academic Dishonesty (Senate For more information see the Academic Integrity & Academic Dishonesty (Senate Policy 49-20) at http://www.psu.edu/ufs/policies/ or Behrend’s Academic Integrity Policy 49-20) at http://www.psu.edu/ufs/policies/ or Behrend’s Academic Integrity policy at http://www.pserie.psu.edu/faculty/academics/integrity.htm.policy at http://www.pserie.psu.edu/faculty/academics/integrity.htm.

Students with disabilities: Students with disabilities: If you have a disability-related need for If you have a disability-related need for modifications or reasonable accommodations in this course, contact the modifications or reasonable accommodations in this course, contact the Disability Specialist in the Office of Student Affairs, Room 115 Reed Disability Specialist in the Office of Student Affairs, Room 115 Reed Union Building, 898-6111.Union Building, 898-6111.

WELCOME to CHEM 213WELCOME to CHEM 213

Purification of Organic SolidsIdentification using Melting Point Determination

Experiment 1

• become familiar with common heating & cooling methods (Technique 6)

• purify organic unknown using recrystallization (Technique 9)

• identify unknown by melting point & solubility data (Technique 10)

Experimental Objectives

RecrystallizationRecrystallization

crystalline material (solute) is dissolved in a hot solvent crystalline material (solute) is dissolved in a hot solvent then returns to solid when cooledthen returns to solid when cooled

important to understand “dissolving”important to understand “dissolving”

http://server1.fandm.edu/departments/chemistry/Van%20Arman%20Virtual%20Lab/Recrystallization/Recrystallization3.html

solid

solvent

choice & amount of solvent is criticalchoice & amount of solvent is critical

SolubilitySolubilitysolvent temperature - solubility increases with temperature

solvent volume - amount of solute vs. volume of solvent

solvent properties - solute/solvent interactions “like dissolves like”

- polar H2O dissolves most (polar) inorganic compounds- nonpolar organic solvents dissolve most (nonpolar) organics

http://bioweb.wku.edu/courses/Biol220CAR/2ChemBond/waterFig.html

Recrystallization Recrystallization SolventsSolvents

Polarity Index Common Name of Solvent Structure

0.0 hexane CH3(CH2)4CH3 (least polar) 2.3 toluene C6H5CH3 2.9 diethyl ether (ether) (CH3CH2)2O 3.4 methylene chloride CH2Cl2 4.3 ethyl acetate CH3CO2CH2CH3 4.3 chloroform CHCl3 5.2 ethanol CH3CH2OH 5.4 acetone (CH3)2C=O 6.6 methanol CH3OH 9.0 water H2O (most polar)

www.chem.umd.edu/organiclabs/Chem232/01Recrystallization/Lab01.ppt

7 Steps to 7 Steps to RecrystallizationRecrystallization

1.1. find “find “best”best” solvent solvent

2.2. dissolve bulk sample in solventdissolve bulk sample in solvent

3.3. decolorize (if necessary) decolorize (if necessary)

4.4. remove insoluble impurities (if necessary)remove insoluble impurities (if necessary)

5.5. cool solute/solvent mixturecool solute/solvent mixture

6.6. collect crystalscollect crystals

7.7. dry & analyze crystalsdry & analyze crystals

Step 1Step 1

1.1. find “find “bestbest” solvent” solvent small (test tube) size using a sand bathsmall (test tube) size using a sand bath dissolves went hot – not when colddissolves went hot – not when cold limited to six initial solvent choiceslimited to six initial solvent choices

waterwater ethanolethanol ethyl acetateethyl acetate methylene chloride (dichloromethane)methylene chloride (dichloromethane) toluenetoluene hexanehexane

Steps 2 - 4Steps 2 - 4

2.2. dissolve bulk sample in solventdissolve bulk sample in solvent minimumminimum amount of solvent to dissolved solute with heat amount of solvent to dissolved solute with heat this will be unique to solute & solvent choicethis will be unique to solute & solvent choice use boiling chips or sticksuse boiling chips or sticks

3.3. decolorize (if necessary)decolorize (if necessary) charcoal adheres to colored impuritiescharcoal adheres to colored impurities

4.4. remove insoluble impurities (if necessary)remove insoluble impurities (if necessary) hot gravity filtrationhot gravity filtration

Hot FiltrationHot Filtration

Hot Plate

Step 5Step 5

5.5. cool solute/solvent mixturecool solute/solvent mixture cool slowly to eliminate soluble impurities from cool slowly to eliminate soluble impurities from

crystallizingcrystallizing

If crystals do not form try…If crystals do not form try… scratching with glass stir rodscratching with glass stir rod add a seed crystaladd a seed crystal evaporate some excess solventevaporate some excess solvent

http://wulfenite.fandm.edu/labtech/crystals.htm

Step 6Step 66.6. collect crystalscollect crystals

vacuum filtration using Buchner Funnelvacuum filtration using Buchner Funnel

to vacuum

Step 7Step 7

7.7. drydry leave on vacuum filterleave on vacuum filter leave crystals in funnel open in deskleave crystals in funnel open in desk heat under a heat lamp – take careheat under a heat lamp – take care

Review Steps 2 – 6: videoReview Steps 2 – 6: videohttp://server1.fandm.edu/departments/chemistry/Van%20Arman%20Virtual%20Lab/Recrystallization/recrystallization1.mov

Percent RecoveryPercent Recovery

evaluates recrystallization quantitativelyevaluates recrystallization quantitatively do not forget to record weight of unknowndo not forget to record weight of unknown not the same as a percent yieldnot the same as a percent yield

% =amount of solid recovered

amount of initial solid X 100

Melting PointsMelting Points temperature where solid & liquid phases in equilibrium characteristic physical property of solid

the identity of an organic solid the purity of an organic solid

most organic solids melt 25 - 250 oC

A. Sublimation B. Melting C. Evaporation

Melting PointsMelting Points

Organic molecules within the solid are held together

by intermolecular forces

Hydrogen bonding 2 – 10 kcal/mol

Dipole-dipole interactions 0.5 - 2 kcal/mol

Van Der Waals forces (temporary dipole) 0.5 kcal/mol

compare to a intramolecular covalent bond ~100 kcal/mol

O

O

HO

O

benzoic acid ethyl benzoate ethyl benzene

Melting PointsMelting Points

Consider the effects of intermolecular forces on the melting point of three organic compounds of similar mass:

Hydrogen BondingHydrogen Bonding

O

OH

O

OH

O

OH

O O

H

O O

H

Benzoic acidmelting point 122-3 oC

Ethyl benzoate, melting point -23 oC

Dipole-DipoleDipole-Dipole

CO

O

CO O

Dipole-dipole interactions are weaker. Ethyl benzoate is heavier than benzoic acid, yet its melting point is below room temperature, almost 150o below benzoic acid.

Van Der WaalsVan Der Waals

Ethyl benzene, melting Point -95 oC

Temporary dipoles are the weakest form of intermolecular force.Solids held together by these forces have low melting points.

The energy (heat) required to break these intermolecular interactions is the same for any two molecules within the solid

• pure organic compounds have a distinct melting point that can be used for identification

• melting point should also occur over a very narrow range of temperatures

• impurity in the solid disrupts intermolecular forces – takes less energy to melt solid – therefore lowering and broadening melting point range

Melting Point DeterminationMelting Point Determination

Pure SolidPure Solid

The Van Der Waalsforces that hold the solid together are regularare the same frommolecule to molecule

Pure naphthalenemelts at 82-83oC

Impure SolidImpure Solid

cyclohexane contaminatednaphthalene, mp 62-69oC

Problem:

Suppose you are cleaning the chemical stockroom and you encounter a reagent bottle whose label has decomposed. You suspect that the compound could be either benzoic acid (mp 122-123 oC) or succinimide (mp 123-5 oC). You take a melting point, and sure enough the unknown melts at 123 oC.

How would you use what you have learned to determine the true identity of the contents of the bottle?

Melting Point DeterminationMelting Point Determination

Mixed Melting PointMixed Melting PointSolution:

obtain known samples of benzoic acid & succinimide mix each of the known samples with a portion of the unknown determine the melting point for each mixed sample

Temp (◦C)

MP Pure AMP Pure B

100% A 100% BMole % Composition

• silicone oil bath

• five samples simultaneously

• oil slow to respond to temperature changes – so a slower, better melting point can be obtained

• silicone oil has a temp limit 200 °C

• good choice for organics that melt between 20-200 °C

Thomas-Hoover

• uses a heated aluminum block

• three samples simultaneously

• aluminum is quick to respond to temperature changes – higher temps can be achieved more quickly

• advantage in determining high melting points

• good choice for organics that melt over 200 °C

Mel-Temp

Use the minimum amount of sample & slowest heating rate to obtain the sharpest, most accurate melting point.

MP Sample SizeMP Sample Size

Sample size: samples placed in a mpcapillary tube. Use the minimum amountseen through the magnifier (1-2 mm)

Heating Rate: quickly go to20 °C below the expected MP,then slow to 1-2 °C per minuteto observe the correct MP

Melting Point Video

IntroductionIntroduction

Brief Paragraph (2-5 sentences)Brief Paragraph (2-5 sentences) interesting background informationinteresting background information goals/objectivegoals/objective reaction (if applicable)reaction (if applicable) proper referenceproper reference

Do not include:Do not include: explanationexplanation procedureprocedure

ConclusionConclusion

Brief Paragraph (2-3 sentences)Brief Paragraph (2-3 sentences) statement summarizing discussionstatement summarizing discussion must include must include conclusionconclusion

Typed, 12 point black font, double spacedTyped, 12 point black font, double spaced grammar, spelling, etc.grammar, spelling, etc.

NotebookNotebook

Chapter 3 in MohrigChapter 3 in Mohrig table of contents (leave room)table of contents (leave room) numbered pages (no pages torn out)numbered pages (no pages torn out)

PrelabPrelab title, datetitle, date purpose including balanced reaction (if applicable)purpose including balanced reaction (if applicable) chemical data tablechemical data table do not write out the proceduredo not write out the procedure (outline if helpful) (outline if helpful)

ObservationsObservations in class notes recorded in inkin class notes recorded in ink calculationscalculations

Questions?Questions?

Comments?Comments?