1. Each substance has unique properties, which enables chemists to distinguish it from other substances
2. Chemists consider benefits and risks in making decisions about chemical processes

1. Create no waste
2. Nothing should be left over
3. No toxicity
4. Green products have to work as well as nongreen products
5. Get rid of all nonessential additives
6. Reduce energy usage
7. Use renewable materials
8. Get rid of as many steps as possible
9. Make use of a reusable method to speed up a reaction
10. Use materials that break down in the environment (biodegradable)
11. Check everything you do against the other principles
12. Safety first

• Aka “the atom economy principle”
• The less that is left over, the better
• Atom economy compares the mass of the desired product (D) to the total mass of products (T)
– Atom economy = D/T *100 (write in lab notebook)
– A measure of how green, or efficient, a chemical process is
• When does atom economy = 100%?

2H
2
O
2
 2H
2
O + O
2
If water is the desired product
Atom economy = 2(18.015) x 100 = 52.96%
[2(18.015)+32]

Percent yield = actual yield X 100 theoretical yield

• Write a BRIEF overview of the question; write your answer below it
• Work quickly

• Look back to the dehydration lab
• Compare atom economy with percent yield
• Write a BRIEF overview of the question; write your answer below it
• Work quickly

• Design a procedure to separate a mixture of sodium bicarbonate and sodium carbonate
– Rxn: solid sodium bicarbonate (with heat)  sodium carbonate, gaseous carbon dioxide, and gaseous water
• Calculate the percentage of each in the original mixture
• Review a lab report as a lab group
• Next class: you’ll carry out your procedure and review the lab report

In your lab notebook
• Guiding principles
• Equation for atom economy
• Questions and answers for
Prelab I and Prelab II questions
• Procedure
• Data table
• Calculation to determine percent of each substance in the mixture
• Postlab questions and answers
Not in lab notebook
• Critique of a lab report written by another scientist
– one per lab group
***Each group will turn in copies from each person’s lab notebook and a lab report critique. Most of the lab will be spot-checked for completeness; your calculations/data analysis will be checked for accuracy. Penalties will count against the individual. The lab report critique (one copy, done by the group) will be the primary grade.