Industrial Chemistry Flashcards
What is atom economy
A method deciding how effective a reaction is
Measures amount of atoms wasted when a chemical is manufactured
100% atom economy- All reactant atoms converted to desired product
The higher the figure the more environmentally friendly the process (less waste)
Why is achieving the highest percentage yield possible important
It reduces cost
Minimise wasting reactants
Why is achieving the highest atom economy important
Reduce unwanted products
Make the process more sustainable
What are exothermic reactions
Reactions accompanied by a temperature rise
Heat energy is given out to the surroundings
Releases more energy when bonds are made than required to break bonds
BONDS ARE MADE
What are endothermic reactions
Reactions accompanied by a fall in temperature
Heat energy absorbed from surroundings
Requires more energy to break bonds than is released when new bonds are made
BONDS ARE BROKEN
What type of reaction does this describe:
A chemical reaction that requires more energy to break bonds than is released when new bonds are made
Endothermic reaction
What type of reaction does this describe:
A chemical reaction that releases more energy when bonds are made than is required to break bonds
Exothermic reactions
What is a batch process
Makes product on demand on a small scale
More labour intensive as reactor needs to be filled, emptied and cleaned
What is a continuous process
Reactants continually fed into the reactor and only one type of product is continually produced
Operates all the time on a large scale and runs automatically
What are the steps to extract material from a natural source to make a medicine
Crushing- eg. mortar and pestle
Dissolving- suitable solvent is added to dissolve material. Boiling improves extraction
Chromatography- concentrated solution of material separates on chromatography paper
Why are labour costs high for developing and researching medicines
Research cannot be automated, it takes years also
Highly qualified scientists required to make decisions (costly)
It must go through further development and testing
It must then be approved and satisfy legal requirements before sale but some countries have strict legal rules regarding testing and sales
Why are medicines expensive
The materials could be rare or require complex methods to extract the raw materials
Made in small quantities and manufacturing can’t be fully automated
Must be as pure as possible to avoid side effects (impurities)
Labour intensive,staff costs are high
Marketing is expensive
Why is yield not always 100%
Reactants haven’t finished reacting
Some solution might be stuck to container
Product may have eveporated or spilled out
Percentage yield compares what
What is a 100% yield
What is a 0% yield
Percentage yield compares: Actual yield (product made) with Predicted yield (product expected to be made)
100% yield- No product has been lost (actual yield= predicted yield)
0% yield- no product has been made ( actual yield= 0 )
What is the formula to calculate energy per gram
Energy per gram= energy supplied/mass of fuel burnt
