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Unit 3: Quantifying Chemical Change Notebook Labs

View Scoring Rubrics (link coming soon)

The following items should be in the Unit 3 portion of your notebook.  They should be clearly organized and easy to find.  Use an organizational system and label all work. Each lab will be graded separately.  All lab grades will be entered into the gradebook. 





Lab QCC1 - The H2O Challenge Lab

Question:
How can _____ x 1023 molecules of dihydrogen monoxide be counted out and retrieved?

Purpose:
To count out and retrieve _____ x 1023 molecules of dihydrogen monoxide and to bring them to the teacher. (The blank will be filled in when you arrive at your lab station.)

Safety:
There are no safety concerns associated with this lab.

Disposal:
The water should be drained and the graduated cylinder should be left on the lab table.

A complete lab write-up includes a Title, a Purpose section, a Data section, and a Conclusion/Discussion section.  The Data section should include a short but organized and labeled calculation showing how _____ x 1023 molecules of dihydrogen monoxide can be related to a measurable amount of mass or volume. A teacher check off box should be included in the Data section (and checked off by the teacher if successful). The Conclusion/Discussion should include a short paragraph explaining how to count out _____ x 1023 molecules of dihydrogen monoxide.








Lab QCC2 - Chew on This! Lab , a.k.a., Hey Sugar! ; ) The Sequel

Question:
What is the percent sugar in bubble gum? What is the empirical formula for bubble gum (as written in the form of GmxSuy where Gm is the the fictional elemental symbol for Gum and Su is the fictional elemental symbol for Sugar)?

Purpose:
To determine the percent sugar in bubble gum and to write an empirical formula for bubble gum in the form of GmxSuy where Gm is the the fictional elemental symbol for Gum (513 g/mol) and Su is the fictional elemental symbol for Sugar (342 g/mol).

Safety:
Chewing on sugared gum can lead to tooth decay.  Chewing on old, stale gum can lead to a chipped tooth. Otherwise, there are no safety concerns associated with this lab.

Disposal:
The chewed gum can be attached to the bottom of your classroom desk or chair when done so that others can stick their finger in the gross, sticky mess.  The chewed gum should be placed in the garbage can.

A complete lab write-up includes a Title, a Purpose section, a Data section, and a Conclusion/Discussion section.  The Data section should include your measurements and all your calculations.  Measurements should be clearly labeled with a unit and the indicated quantity.  Calculations should be organized and labeled with units and the indicated quantity; work should be shown.  The logic behind each calculated step should be briefly annotated using 1-2 sentences.  Attention should be given to units and significant digits. The Conclusion should use a brief sentence to indicate the answer to the question posed in the purpose of the lab.









Lab QCC3 - Magnesium Oxide Analysis

Question:
What is the percent composition and empirical formula of magnesium oxide?

Purpose:
To experimentally determine the percent composition and empirical formula of magnesium oxide (in the form of Mg1Ox).

Safety:
Goggles must be worn at all times (as always). Magnesium is quite flammable and gives off an intense flame but we don't want it to flame. Hot crucibles look like cold crucibles and should never be handled with fingers; use tongs and always be aware of the burn hazard.  Keep your face at arm's length from the crucible; wear goggles at all times (as usual).  Smoke will be produced from the burning of magnesium; keep your crucible covered and do not inhale the smoke.  Give attention to the provided directions.

Disposal:
The solids should be placed in the garbage can. All equipment should be thoroughly cleaned and set aside to dry. Lab tables should be thoroughly rinsed before leaving lab. Wash your hands thoroughly with soap and water before leaving the lab.

A complete lab write-up includes a Title, a Purpose section, a Data section, and a Conclusion/Discussion section.  The Data section should include an organized record of the collected data;  measurements should be labeled with units and the indicated quantity.  Calculations should also be clearly organized and labeled with units and the indicated quantity. The logic of each calculation should be briefly annotated with 1-2 short sentences of reasoning. The result of the series of calculations should be the ratio of moles of O to the moles of Mg and the experimentally derived formula. The Conclusion/Discussion should include a brief sentence indicating the answers to the two questions posed in the purpose of the lab. An error analysis should also be included in which the results are evaluated for their accuracy. A percent error calculation comparing the experimental and theoretical value of x should be incorporated into the Discussion; the work should be clearly shown.










Lab QCC4 - Copper and Silver Nitrate Lab

Question:
What is the experimentally determined mole ratio of copper(II) to silver in the single replacement reaction of silver nitrate with copper?

Purpose:
To use careful measurements to determine the mole ratio of copper(II) and silver in the single replacement reaction of silver nitrate with copper.

Safety:
Nitric acid is corrosive and a strong oxidizer.  Silver nitrate is corrosive, toxic by ingestion and will stain your skin and clothing.  Acetone is extremely flammable.  Goggles should be worn at all times.

Disposal:
Undissolved solids should never be poured down the drain; instead, they should be placed in a garbage can.  All other solutions can be poured in the sink and thoroughly rinsed down the drain.

A complete lab write-up includes a Title, a Purpose section, a Data section, a Conclusion, and a Discussion section.  The Data section should include the results of your measurements and all calculations.  Measurements should be recorded in a table and clearly labeled with a unit and the indicated quantity.  You will need to calculate the mass and number of moles of reactants: AgNO3 and Cu and of the measured product: AgCalculations should be organized and labeled with units and the indicated quantity.  The logic behind each calculated step should be briefly annotated.  Attention should be given to units and significant digits. The Conclusion should use a brief sentence to indicate the answer to the question posed in the purpose of the lab.  The Discussion of Results should include an error analysis.  Like all error analyses, you should respond to the question How did we do?  This means you should discuss the expected answer to the question (a balanced chemical equation would help) and compare the expected answer to the experimental answer.  A percent error calculation should be included and discussed;  the work should be clearly shown.  Specific sources of error should be identified.

View Directions.










Lab QCC5 - Copper Cycle Lab

Question:
What is the percent yield of copper after a series of reactions involving copper and copper-containing compounds?

Purpose:
To use good lab skills in order to determine and maximize the percent yield of copper in a series of reactions involving copper and copper-containing compounds.

Safety:
Nitric acid is corrosive and a strong oxidizer.  The reaction of nitric acid with copper produces a poisonous gas;  this MUST be done in the fume hood.  Hydrochloric acid is corrosive to eyes, skin and clothing.  Exercise caution when working around a hot water bath.  Sodium hydroxides is corrosive and can cause skin burns.  Acetone is flammable;  keep away from flames.

Disposal:
Undissolved solids should never be poured down the drain; instead, they should be placed in a garbage can.  All other solutions can be poured in the sink and thoroughly rinsed down the drain.

A complete lab write-up includes a Title, a Purpose section, a Data section, a Conclusion, and a Discussion of Results section.  The Data section should include observations for each part of the copper cycle process;  balanced chemical equations should be written for each part of the experiment.  The Data section should also include the results of your measurements and all calculations.  Measurements should be recorded in a table and clearly labeled with a unit and the indicated quantity.  Calculations should be organized and labeled with units and the indicated quantity.  The logic behind each calculated step should be briefly annotated.  Attention should be given to units and significant digits. The Conclusion should use a brief sentence to indicate the perent yield.  The Discussion of Results section should an error analysis.  At least two procedural problems which lead to less than 100% recovery of copper should be identified and discussed.  At least two procedural problems which lead to more than 100% recovery should be identified and discussed.

View Procedure.










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