Green Chemistry Quiz 1

Green chemistry

-Resources are scarce

-Want to have chemical reactions that are the most ECONOMIC and good for the ENVIRONMENT

* Want efficient rxns

* High yields

* Pure products

Optimize reactions

Yield

the amount of product obtained in a chemical reaction

Selectivity

selecting for one reaction to occur over another

Ex: Sn2 vs. E2

Co products

-Waste products that are INEVITABLE

-Inevitability of mechanism

By products

-Waste products that are formed from ERROR

-Poor chemistry has been done

Utilized atoms

-Atoms in PRODUCTS

-Atoms which were utilized from reagent/starting material

Unutilized atoms

-Atoms in reagent/starting materials

-Do not appear in DESIRED product***

Wasted atoms

Atom economy

Mass of useful product / mass of all reactants

Mass of all utilized atoms / mass of all atoms in reagents

** Shows what mass went to waste in RXN

Experimental atom economy

Theoretical yield mass / Mass of all reactants

** Shows what mass will/should go to waste in RXN

Theoretical yield

-Maximum amount of product that can be made from a reaction

-Reaction goes 100% complete

Percent yield

actual yield/theoretical yield x 100

MOST important / Shows the most "greenness"

PY x EAE

Percent yield of rxn X experimental atom economy

Shows the overall "greenness" of a reaction

12 Principles of Green Chemistry

1. Prevention

2. Atom economy

3. Less hazardous chemical synthesis

4. Design safer chemicals

5. Safer solvents and auxiliary

6. Design for energy requirement

7. Use of renewable feedstocks

8. Reduce derivatives

9. Catalysis

10. Design for degradation

11. Real-time analysis for pollution prevention

12. Inherently safer chemistry for accident prevention

Prevention

-Prevention is better than fixing an issue after it occurs

"It is better to prevent waste than to treat or clean up waste after it has been made"

Atom economy

-Design reactions which will utilize the most starting material / produce the lease amount of waste possible

"Synthetic methods should be designed to maximize incorporation of all materials used in the process into the final product"

Less hazardous chemical synthesis

-Make/use the least hazardous chemicals possible

"Wherever practical, synthetic methods should be designed to use/generate substances that posses little toxicity"

Design safer chemicals

-Create safer chemicals in lab, while maintaining same efficacy

"Chemical products should be designed with reduced toxicity (same efficacy)"

Safer solvents and auxiliary

-Only use accessory reagents (solvents, separator agents, etc) when necessary

"The use of auxiliary agents should be reduced"

Design for energy requirements

-Create/choose reactions with the least energy requirement -- Understand environmental and economic impact

"Recognize the financial/environmental costs of energy needs; try to reduce them"

Use of renewable feedstocks

-Use renewable resources; don't deplete un-renewable ones

Reduce derivatives

-Only use materials that are necessary in a reaction

"Unnecessary derivativization (use of blocking agents, protecting/activating groups) should be reduced. It requires more reagents and generates more waste"

Catalysis

-Catalytic reagents are superior to stoichiometric reagents

Design for degradation

-Design chemicals to break down

-Environmentally friendly

-Don't design chemicals that will persist in the environment

Real-time analysis for pollution prevention

-Design a method to monitor/control production of hazardous waste BEFORE it is created

** prevent pollution

Inherently safer chemistry for accident prevention

-Choose the safest chemical reagents/mechanisms possible

"Choose substances to minimize the potential for chemical accidents, including releases, explosions, and fires"