1. Definition
Green chemistry is “the design of
chemical products and processes
that reduce or eliminate the use and
generation of hazardous substances”.

2. 12 Principles of Green Chemistry
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7. Maximize atom economy
What’s atom economy ?

3. Atom economy describes the conversion
efficiency of a chemical process in terms of all
atoms involved. In an ideal chemical process
the amount of starting materials or reactants
equals the amount of all products generated
and no atom is wasted. Recent developments
like the advent of Green chemistry and high
raw material (oil) prices increasingly demand
high atom economy.

4. It is possible to calculate how
successful one of these processes is
by using the idea of yield
Mass of product actually made
% Yield = _______________________ X 100
Maximum mass of product that
could be made(theoretical yield)

5. If 50 kg calcium carbonate is used and 21 kg
calcium oxide is made, what is the percentage
yield of the reaction?
theoretictal yield = 28kg calcium oxide
21kg
% yield = _____________ x 100 = 75%
28 kg

6. A reaction can have a high percentage
yield but also make a lot of waste product.
This kind of reaction has a low atom
economy.