Beacon Lesson Plan Library

Mystery of the Eleven Unknown Substances

Jo Ann Parsons

Description

This is an easy outline for students to follow for identification of eleven white substances that are commonly found in the household.

Standards

Florida Sunshine State Standards
SC.A.1.4.5
The student knows that connections (bonds) form between substances when outer-shell electrons are either transferred or shared between their atoms, changing the properties of substances.

Florida Process Standards
Information Managers
01 Florida students locate, comprehend, interpret, evaluate, maintain, and apply information, concepts, and ideas found in literature, the arts, symbols, recordings, video and other graphic displays, and computer files in order to perform tasks and/or for enjoyment.

Effective Communicators
02 Florida students communicate in English and other languages using information, concepts, prose, symbols, reports, audio and video recordings, speeches, graphic displays, and computer-based programs.

Effective Leaders
09 Florida students establish credibility with their colleagues through competence and integrity and help their peers achieve their goals by communicating their feelings and ideas to justify or successfully negotiate a position which advances goal attainment.

Materials

Test Reagents: NOTE: No more than 50 ml of any reagent should be allowed!
-Phenolphthalein (Laxative tablets)
-Isopropyl alcohol (70%) rubbing alcohol
-Iodine (Tincture of Iodine)
-Vinegar (white Vinegar)
-Water (Tap water)
-Copper (II) sulfate crystals
-Sodium hydroxide
-Sodium Carbonate

Supplies:
-Test tubes or spot plates
-Droppers
-Funnels
-Filter paper
-PHydrion or litmus paper
-Spatulas, scapulas
-Test tube rack and test tube holder
-Distilled water
-A hand lens
-A hot water bath for each group.

Substances:
-Sodium chloride (Plain table salt- Uniodized)
-Sodium bicarbonate (Baking soda)
-Sodium carbonate (washing soda)
-Sodium hydroxide (Drain Opener)
-Boric acid
-Calcium sulfate (Plaster of Paris)
-Calcium carbonate (White chalk or calcium supplement tablets)
-Cornstarch
-Fructose (Fruit sugar (Estee Brand)
-Sucrose (Table sugar)
-Magnesium sulfate (Epsom salts)
-Ammonium chloride

Preparations

1. Equipment set up for each group in each class is time consuming. Be sure you have plenty of materials to go around.
2. Fructose may be hard to find. Try a Natural Food Store.
3. Make up Benedicts Solution prior to lab.

Procedures

Follow the schematic on the attached handout to observe the properties of the eleven known substances. Then you will receive 2 unknown substances and 1 mixture of three substances to properly identify using the same procedures.
You must never taste materials!!!!!

Part I
1. Fill in the Analysis chart using correct formulas for compound names. Record any notes and observations you would like to make on the process in your lab notebook.

2. Students write balanced and net equations for each reaction taking place in any test unless instructed otherwise.

3. Students write down why reactions produced color changes, precipitates, or other observations.

Part II
1. When students have completed the above process, they receive 2 unknown samples chosen from the 11 original substances and 1 mixture with three substances combined to correctly identify. Provide students with only 1 teaspoon of any solid.

2. Students write balanced equations and net equations to represent the reaction-taking place in your unknown samples.

3. Students respond orally to 4 questions by explaining, "Why some observation would occur in the Analysis scheme." (Anything can be asked in the lab, not just the unknowns)

Encourage students to have fun! They should pay attention, work together, keep up with their lab group, ask questions, look up answers, and search for clues and information. Students strive to learn as much as they can from this opportunity to investigate!

Assessments

Assess students by the correct completion of the Lab Handout, their lab reports containing observations and Net Ionic equations, and by the correct identification of their unknowns. Also assess students by their responses to the four questions asked about the lab and by demonstration of proper lab techniques.

Extensions

More Extensive Qualitative Analysis Labs or Labs where students are allowed to devise their own Analysis Scheme.

Attached Files

Qualitative Analysis Tests     File Extension: pdf

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