Chemistry LabChemistry Lab

By Linda WozniewskiBy Linda Wozniewski

lwoz@iun.edulwoz@iun.edu

What do they need to be able to do What do they need to be able to do every year every year? every year every year?

Interpretation of Interpretation of experimental data experimental data (tabular and/or graphic) (tabular and/or graphic)

Observation of an Observation of an experiment set up and experiment set up and running running

Computer or calculator Computer or calculator sensors/probes sensors/probes

Stoichiometry : mole Stoichiometry : mole conversions and conversions and percentage yieldpercentage yield

Nomenclature and Nomenclature and formula writing - symbols formula writing - symbols and charges for the and charges for the following ions by memory: following ions by memory: nitrate, carbonate, nitrate, carbonate, phosphate, acetate, phosphate, acetate, sulfate, ammonium, sulfate, ammonium, bicarbonate, and bicarbonate, and hydroxide (“ite” forms of hydroxide (“ite” forms of “ates” listed) “ates” listed)

SafetySafety

Students must wear:Students must wear: Closed shoesClosed shoes Slacks or skirts that come to the anklesSlacks or skirts that come to the ankles Sleeved shirtsSleeved shirts Lab coat or lab apronLab coat or lab apron Indirect vent or unvented chemical splash Indirect vent or unvented chemical splash

proof goggles. No impact glasses or proof goggles. No impact glasses or visorgogs are permittedvisorgogs are permitted

What the Students Should BringWhat the Students Should Bring

Safety gearSafety gear

Something to write withSomething to write with

What the Students Should Not BringWhat the Students Should Not Bring

Anything else

This includes notes

What the Supervisor ProvidesWhat the Supervisor Provides

Everything the student will needEverything the student will need

How to prepare participantsHow to prepare participantsMake sure students read the directions and pay Make sure students read the directions and pay particular attention to the description of the particular attention to the description of the event (The Competition) event (The Competition)

Have them do many experiments together Have them do many experiments together

Have them determine their individual strengths Have them determine their individual strengths

Divide (and conquer) tasks during competition Divide (and conquer) tasks during competition

Check each other’s work Check each other’s work

How to prepare participantsHow to prepare participants

Get as many lab books from your Get as many lab books from your chemistry teacher as possible & have chemistry teacher as possible & have students explore labs by topic and do the students explore labs by topic and do the ones that appear consistently ones that appear consistently

Changes for 2009 Changes for 2009

2 new topics: 2 new topics: KineticsKinetics Aqueous Solutions Aqueous Solutions

KineticsKineticsStudents will demonstrate an understanding of Students will demonstrate an understanding of

the principals of kinetics. They must be able the principals of kinetics. They must be able to measure reaction rates and identify how to measure reaction rates and identify how and why reaction conditions (temperature, and why reaction conditions (temperature, concentration, particle size, and catalysts) concentration, particle size, and catalysts) affect reaction rates. At the regional level, affect reaction rates. At the regional level, teams will NOT be asked to determine rate teams will NOT be asked to determine rate laws experimentally or from data provided. laws experimentally or from data provided. At the state and national levels, teams will be At the state and national levels, teams will be asked to determine rate laws from actual asked to determine rate laws from actual experimentation or data provided, and teams experimentation or data provided, and teams should also be able to determine rate should also be able to determine rate constants with correct unitsconstants with correct units

KineticsKinetics

Calculating a rateCalculating a rate Fair game at Regional CompetitionsFair game at Regional Competitions

[] means the concentration of[] means the concentration of

Rate LawRate Law Can only be done at State and NationalCan only be done at State and National Rate = k[A]Rate = k[A]xx[B][B]yy……

time

reagent] [limiting Rate

Kinetic Activities Kinetic Activities Iodine Clock Reaction – one of the most Iodine Clock Reaction – one of the most famous & widely used kinetic reactionsfamous & widely used kinetic reactions

Very easy to do, but very hard to explain Very easy to do, but very hard to explain all of the chemistryall of the chemistry

http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA3/MAIN/CLOCKRX/PAGE1.HTM

For a really cool oscillating reaction (if you For a really cool oscillating reaction (if you have the resources)have the resources)

http://chemistry.about.com/cs/http://chemistry.about.com/cs/demonstrations/a/aa050204a.htmdemonstrations/a/aa050204a.htm

Kinetic ActivitiesKinetic Activities

To see the effects of surface area To see the effects of surface area

Reaction of Powdered Sugar and Granular Reaction of Powdered Sugar and Granular Sugar with concentrated HSugar with concentrated H22SOSO44

http://www.exo.net/~pauld/activities/http://www.exo.net/~pauld/activities/astronomy/transitvenus/astronomy/transitvenus/sugarsulfuricacid.htmsugarsulfuricacid.htm

Kinetic ActivitiesKinetic Activities

To see the effects of concentration on To see the effects of concentration on kinetics, trykinetics, try

Reaction of mossy zinc in 2 M CuSOReaction of mossy zinc in 2 M CuSO44 & .2 & .2

M CuSOM CuSO44

Kinetics ActivitiesKinetics Activities

To see the effect of temperature, try a To see the effect of temperature, try a simple baking soda and vinegar simple baking soda and vinegar experiment at different temperatures.experiment at different temperatures.

Kinetics ActivitiesKinetics Activities

http://chemistry.about.com/od/http://chemistry.about.com/od/stoichiometry/a/reactionrate.htm stoichiometry/a/reactionrate.htm

Aqueous SolutionsAqueous SolutionsStudents will demonstrate an understanding of the Students will demonstrate an understanding of the principals and properties of aqueous solutions. principals and properties of aqueous solutions. They must be able to calculate solution They must be able to calculate solution concentrations given quantities of solute and concentrations given quantities of solute and solvent, and to calculate quantities of material solvent, and to calculate quantities of material required to produce a solution of specified required to produce a solution of specified concentration. Molarity, molality, mass concentration. Molarity, molality, mass percentage, and parts per million may be required. percentage, and parts per million may be required. Students are also required to demonstrate an Students are also required to demonstrate an understanding of colligative properties. At the understanding of colligative properties. At the state and national levels, conversions between state and national levels, conversions between concentration units may be required.concentration units may be required.

Aqueous ActivitiesAqueous ActivitiesUse the concept of density to experimentally Use the concept of density to experimentally determine the concentration of a solution.determine the concentration of a solution.Determine solution concentration using a series of Determine solution concentration using a series of standard absorbencies and Beer’s Law.standard absorbencies and Beer’s Law.Use freezing point depression to determine the Use freezing point depression to determine the molar mass of a solute.molar mass of a solute.Use titration to determine an unknown concentration.Use titration to determine an unknown concentration.Identify and explain factors that effect solution Identify and explain factors that effect solution formation.formation.Construct a solubility curve.Construct a solubility curve.Determine whether a solution is saturated, Determine whether a solution is saturated, unsaturated or supersaturated unsaturated or supersaturated

Aqueous ActivitiesAqueous Activities

http://chemtutor.com/mols.htm#dv

http://web.archive.org/web/http://web.archive.org/web/20070505005726/library.thinkquest.org/20070505005726/library.thinkquest.org/10429/low/sol/sol.htm10429/low/sol/sol.htm

Resources: TI Activity Exchange Resources: TI Activity Exchange

http://education.ti.com/educationportal/http://education.ti.com/educationportal/activityexchange/BrowseResult.do?activityexchange/BrowseResult.do?cid=US&subName=Science&subAreaNamcid=US&subName=Science&subAreaName=Chemistry&subAreaId=5028&catName=e=Chemistry&subAreaId=5028&catName=Kinetics&catId=1097&aCount=6&brsOpenKinetics&catId=1097&aCount=6&brsOpenNode=bt1.o%2816%29Node=bt1.o%2816%29

ScoringScoring

50% Kinetics 50% Kinetics

50% Aqueous Solutions50% Aqueous Solutions

Questions?????Questions?????

Thank youThank you