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Safety Reference
Greening the School Science Lab, continued
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include acid–base titrations of fruit juices, redox reactions using Vitamin C as a reduc- ing agent, paper chromatography of food dyes, and the preparation of biodiesel.
• Teach fundamental principles in environ- mental chemistry and biology.
− Determine the alkalinity or buffer capacity of water by acid–base titration.
−Use the Winkler method to measure dissolved oxygen concentrations in water as a function of nutrient levels, such as nitrate and phosphate ions.
− Compare the ability of soil versus sand to bind nutrients and exchange ions using ionic indicator dyes.
− Simulate the production and the properties of acid rain.
− Investigate how the specific heat of geolog- ical materials such as sand, soil, and water influence climate.
• Look for lab activities to teach recent advances in science and technology. Interesting kits we have developed in recent years include building a solar cell, prepar- ing and testing biodiesel fuel made from vegetable oil, and demonstrating the prop- erties of “colloidal gold” nanoparticles. Please consult the index to find these kits and many more!
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−Sodium chlorate is more stable than potassium chlorate for small-scale oxygen generation.
−Ammonium chloride is less hazardous than ammonium nitrate for endothermic solution experiments.
−Prepare bromine solutions in water (“bromine water”).
−Use methyl tert-butyl ether rather than diethyl ether for extraction procedures.
• Perform a modern variation of the classic Boyle’s law experiment using a syringe in a special pressurized soda bottle—get rid of the mercury-filled column.
• To determine molar volume, generate hydrogen gas (from magnesium and hydro- chloric acid) instead of oxygen, which requires dangerous potassium chlorate.
• • •
Use sodium hypochlorite rather than sodium dichromate as an oxidizing agent (the latter is a carcinogen).
For the synthesis of a coordination compound, use an iron compound instead of nickel or cobalt.
Incorporate applications-oriented lab activ- ities into the curriculum wherever possible to make the experiments more interesting to students while at the same time reducing the use of hazardous chemicals. Examples
Notice that Green Chemistry does NOT mean doing fewer labs, “dumb- ing down” the curriculum, or teaching less science! In fact, the opposite is true. By practicing green chemistry across the curriculum, you will be able to teach the same concepts and accomplish the same learning goals. More importantly, you will feel better knowing that you’re making a posi- tive contribution to the environment and to science education by empow- ering and exciting the next generation of scientists.
See the “Boyle’s Law in a Bottle” Student Laboratory Kit (Catalog No. AP6855) on flinnsci.com for a description of this environmentally friendly Boyle’s law experiment.
Green Chemistry Laboratory Kits
By: The Flinn Staff and Beyond Benign
Green Chemistry: Making a Household
Surface Cleaner—Student Laboratory Kit
Catalog No. AP8365
Convert a plastic cup into a household surface cleaner with chemis- try! Use this experiment to demonstrate the utility of chemistry as an enabler of positive climate gains in both introductory and advanced courses. Complete for 30 students working in pairs.
Green Chemistry: Design and Function— Blackberry Solar Cell—Student Laboratory Kit
Catalog No. AP8366
Use fruit to build a dye-sensitized solar cell (DSC) and measure its electrical characteristics. This lab introduces students to a huge number of chemistry topics including materials chemistry, alternative energy, solid state chemistry, electrochemistry, sustainability, green chemistry and nanotechnology. Moreover, students observe the direct application of chemistry, as they see evidence for light’s conversion to electricity. Complete for 24 students working in groups of 4.
Green Chemistry: Ash Water Titration—
Student Laboratory Kit
Catalog No. AP8367
This green chemistry version of a strong acid–strong base titration, developed in partnership with Beyond Benign, uses wood ash, a renewable source of base that can be recovered from combusted wood
and organic materials, instead of sodium hydroxide. Complete for 30 students working in pairs.
AP8365
AP8368
Green Chemistry: Road Deicers—
Student Laboratory Kit
Catalog No. AP8368
Students examine the effects of aqueous solutions of sodium chlo- ride, magnesium chloride and calcium chloride on germination and growth of lettuce seeds. The procedure introduces toxicity measurements while using standard equipment and common tech- niques, such as serial dilution and volumetric measurement. The goal of the lab is to identify which of the road deicers is the most
benign with respect to potential environmental impacts. Complete for 28 students working in pairs.
Catalog No.
Description
Price/Each
AP8365
Green Chemistry: Making a Household Surface Cleaner—Student Laboratory Kit
$30.55
AP8366
Green Chemistry: Design and Function— Blackberry Solar Cell—Student Laboratory Kit
67.95
AP8367
Green Chemistry: Ash Water Titration— Student Laboratory Kit
37.35
AP8368
Green Chemistry: Road Deicers— Student Laboratory Kit
51.35