Synthesis Green Metrics (2018) – Solutions
Manual – Andraos
different types of metrics vailable when designing / assessing chemical reactions - answer-
percentage yield, atom economy, e factor, effective mass yield
risk= - answer-hazard x exposure
disadvantages of atom economy - answer-atom economy: focus too much on waste. theoretical
so tell us nothing about reaction yield or selectivity, or nature (toxic/benign) of the waste
system. only take int account stoichiometric reagents (what about catalysts and solvents). atom
economies tell us nothing about other green chemistry concerns (energy/toxicity)
what are atom economies useful for - answer-simple to calculate. comparing waste production
of alternative pathways, but other factors/disadavantages should be considered
disadvantages of E factor - answer-focus too much on waste. doesn't include process water,
what if large volumes of solvent are water, or if the waste consists of dilute aqueous solutions
of benign inorganics?. still concentrated on waste rather than other green factors
advantages of E factor - answer-account for solvent use
how to calculate effective mass yield - answer-mass of desired product/ mass of non-benign
reagents x100
disadvantages of using effective mass yield - answer-how do you decide what is a non-benign
reagent, so calculation one to abuse
1
, advantages of using effective mass yield - answer-account for toxicity if reagents
how to calculate process mass intensity for a given chemical process - answer-total mass in
process/ mass of product DONT X 100
mass productivity = - answer-mass of product/ total mass in process DONT X 100
carbon efficiency = - answer-mass of carbon in product/ mass of carbon in process X 100
when questioning the competing chemical reactions we tend to compare/how can we measure
the greenness of a chemical reaction/ - answer--raw materials
-reaction types (additions, eliminations)
-reagents (caltalysts)
-reaction conditions (including solvents)
-toxicity of producets (including waste products)
talk about 12 principals of green chemistry
what are the 3 spheres of sustainability - answer-environmental, economic, social
social points - answer--standard of living
-education
-communication
-equal opportunity
2
Manual – Andraos
different types of metrics vailable when designing / assessing chemical reactions - answer-
percentage yield, atom economy, e factor, effective mass yield
risk= - answer-hazard x exposure
disadvantages of atom economy - answer-atom economy: focus too much on waste. theoretical
so tell us nothing about reaction yield or selectivity, or nature (toxic/benign) of the waste
system. only take int account stoichiometric reagents (what about catalysts and solvents). atom
economies tell us nothing about other green chemistry concerns (energy/toxicity)
what are atom economies useful for - answer-simple to calculate. comparing waste production
of alternative pathways, but other factors/disadavantages should be considered
disadvantages of E factor - answer-focus too much on waste. doesn't include process water,
what if large volumes of solvent are water, or if the waste consists of dilute aqueous solutions
of benign inorganics?. still concentrated on waste rather than other green factors
advantages of E factor - answer-account for solvent use
how to calculate effective mass yield - answer-mass of desired product/ mass of non-benign
reagents x100
disadvantages of using effective mass yield - answer-how do you decide what is a non-benign
reagent, so calculation one to abuse
1
, advantages of using effective mass yield - answer-account for toxicity if reagents
how to calculate process mass intensity for a given chemical process - answer-total mass in
process/ mass of product DONT X 100
mass productivity = - answer-mass of product/ total mass in process DONT X 100
carbon efficiency = - answer-mass of carbon in product/ mass of carbon in process X 100
when questioning the competing chemical reactions we tend to compare/how can we measure
the greenness of a chemical reaction/ - answer--raw materials
-reaction types (additions, eliminations)
-reagents (caltalysts)
-reaction conditions (including solvents)
-toxicity of producets (including waste products)
talk about 12 principals of green chemistry
what are the 3 spheres of sustainability - answer-environmental, economic, social
social points - answer--standard of living
-education
-communication
-equal opportunity
2
