 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |

Arizona Daily Star 1985 Special Edition on TCE
|
|
Chemistry:
Elements/Compounds Lessons
Big Idea |
Organic solvents, including TCE, have properties that make them useful for particular applications and necessitate their special handling.
|
Essential Question |
What are the properties of organic solvents (ex: TCE) that make them useful for particular applications and necessitate their special handling?
|
Learning Cycle
|
Title |
|
| Engage |
Why
are Solvents so Useful?
description
Students try different methods of dissolving a stain. They also analyze situations at a coffee plant and ViewMaster factory and choose whether to use solvents. They then propose possible drawbacks to use of these chemicals.
objectives
Students will:
*Discover ethanol’s usefulness in dissolving a stain.
*Read accounts of situations at coffee and ViewMaster factories
and decide whether to use solvents.
*Propose possible as-yet-unstated downsides to using new solvents
|
WORD
|
Explore |
How
Much TCE is Allowed by Law in Drinking Water?
description
EPA standards are in ppb because getting rid of all contaminants is impossible, and present techniques have limits in their detection abilities.
objectives
*Perform a serial dilution to 5 ppb, the legal limit for TCE
*Explore detection limits of their own eyes and a spectrophotometer.
*Explain why EPA limits are not 0.
|
WORD
|
Explain |
Costs and Benefits of Solvent Use
description
Students will research general information about TCE- its role as a solvent, its uses, current price and availability, health concerns, environmental concerns, and clean-up techniques..
objectives
*Draw a structural model of TCE, and explain the name
*Analyze the costs and benefits of various clean-up methods
*Explain how solvents work, using the word polarity
*Identify uses, health risks, and alternatives to TCE.
|
WORD 
|
Apply |
Making decisions about TCE
description
What would you decide in real situations when TCE is at issue?
Is TCE still being used?
objectives
*Read accounts of TCE use, disposal, health effects, and subsequent clean-up
in various sites and analyze the situation, offering decisions.
|
WORD 
|
|