Chemistry Lab

1. Chemistry Lab By Lin Wozniewski lwoz@iun.edu

2. Disclaimer • This presentation was prepared using draft rules.  There may be some changes in the final copy of the rules.  The rules which will be in your Coaches Manual and Student Manuals will be the official rules

3. Interpretation of experimental data (tabular and/or graphic) Observation of an experiment set up and running Computer or calculator sensors/probes Stoichiometry : mole conversions and percentage yield Nomenclature and formula writing - symbols and charges for the following ions by memory: nitrate, carbonate, phosphate, acetate, sulfate, ammonium, bicarbonate, and hydroxide (“ite” forms of “ates” listed) What do they need to be able to do every year every year?

4. Safety • Students must wear: • Closed shoes • Slacks or skirts that come to the ankles • Sleeved Shirt (if wearing a lab apron) • Lab coat or lab apron • Indirect vent or unvented chemical splash proof goggles. No impact glasses or visorgogs are permitted

5. What the Students Should Bring • Safety gear • Something to write with What the Students Should Not Bring Anything else This includes notes

6. What the Supervisor Provides • Everything the student will need • This may include: • Glassware • Reagents • Balances • Hot plates • Thermometers • Probes • Magnets • Stirrers

7. How to prepare participants • Make sure students read the directions and pay particular attention to the description of the event (The Competition) • Have them do many experiments together • Have them determine their individual strengths • Divide (and conquer) tasks during competition • Check each other’s work

8. How to prepare participants • Get as many lab books from your chemistry teacher as possible & have students explore labs by topic and do the ones that appear consistently

9. Changes for 2011 • 1 new topic & 1 old topic: • Oxidation/Reduction • Aqueous Solutions

10. Oxidation/Reduction Students must be able to write oxidation and reduction half reactions, assign oxidation numbers, balance redox reactions in neutral, acidic, and basic solutions, and calculate standard cell potentials using a table of standard reduction potentials.

11. Oxidation/Reduction Activities • Use a sequence of redox reactions to construct an activity series • Construct a simple voltaic cell and measure its potential • Stoichiometry and electrochemical processes (such as electrochemical deposition) • Construct simple electrolytic cells. At state and national levels, knowledge of fuel cells may be included • At the state and national levels knowledge and application of the Nernst equation and common storage batteries may be included.

12. Oxidation/Reduction Activities • Series of redox reactions • Small pieces of metal have a drop of another metal’s ion put on them to see if there is a reaction or not • Or a small piece of metal is dropped into a test tube containing another ion’s metal to see if there is a reaction or not. • Chlorine water is added to a solution of a halide and then hexane is added. • A titration of an Iron(II) ion is done with a strong oxidizer such as permanganate or Cerium (IV)

13. Oxidation/Reduction Activities • Electrolysis of water • Can be used as both a redox and aqueous solution activity. • Students can investigate not only the redox reaction involved in the production of hydrogen and oxygen from the water, but the resulting production of hydronium and hydroxide ions.

14. Oxidation/Reduction Activities • Electrodeposition is a broad industrial term that can refer to: • Electroplating • Electrocoating • E-coating • Cathodic electrodeposition • Electrophoretic coating • Electrophoretic painting

15. Oxidation/Reduction Activities • At the state and national levels the Nernst equation may be tested. • Equation usually used at low concentrations.

16. Oxidation/Reduction Activities • http://education.ti.com/educationportal/activityexchange/activity_list.do?cid=us • http://chemtutor.com/redox.htm • http://web.archive.org/web/20050830214525/library.thinkquest.org/10429/low/redox/redox.htm

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

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

19. Aqueous Activities • http://chemtutor.com/mols.htm#dv • http://web.archive.org/web/20070505005726/library.thinkquest.org/10429/low/sol/sol.htm

20. Resources: TI Activity Exchange • http://education.ti.com/educationportal/activityexchange/BrowseResult.do?cid=US&subName=Science&subAreaName=Chemistry&subAreaId=5028&catName=Kinetics&catId=1097&aCount=6&brsOpenNode=bt1.o%2816%29

21. Scoring • 50% Oxidation/Reduction • 50% Aqueous Solutions

22. Resources • For Event Supervisors • http://mypage.iu.edu/~lwoz/socrime/index.htm • For Lesson Plans for classroom use • http://mypage.iu.edu/~lwoz/socrime/index.htm

23. Questions??? • Thank you