The reaction starts when the calcium carbonate and acid are mixed together. Carbon dioxide pushes the plunger out, and its volume is read at regular intervals from the graduations on the gas syringe.
The amount of
product formed is
DIRECTLY
PROPORTIONAL to
the amount of
limiting reactant
Nota:
eg: If the mass of calcium carbonate is doubled, the amount of carbon dioxide also doubles
Industrial Reactions
Continuous Processes
The product is
made all the
time
Used for bulk chemicals which are needed in large amounts
Ammonia in the Haber process
Reactants are
continually fed
into a reaction
vessel, where
they react
together
The ammonia produced is collected all the time
Sulfuric acid
Chlorine
Batch Processes
Not made all the time
Wine
Grapes are pressed to
release the grape juice,
which is then
fermented to produce wine
Speciality Chemicals
High value chemicals needed in small amounts
Made on demand when a customer needs them
Pharmaceuticals
Raw materials
needed may be
made synthetically
using chemical
reactions or
extracted from
plants
Several steps are needed to
extract chemicals from
plants
1. Crush plant material
2. Dissolve in a suitable solvent and then filter
3. Boil to evaporate the solvent
4. Separate the chemical by chromatography
Making medicines
Costs
Research and testing
Nota:
Suitable new substances must be identified, then tested to make sure they are safe and effective.
Tests
Nota:
Thousands of new substances may be made and tested in the development of a new drug.
The 1st tests involve computer simulations and tests on cells grown in the laboratory. The most promising substances are tested on laboratory animals
If it passes these first stages, a substance is checked for side effects in healthy human volunteers. It is then tested on a small group of patients to see if it works as expected, and then on a larger group to gather more information on it.
All stages in development are expensive and time consuming.
Labour costs
Nota:
Many skilled people are needed
Energy
Nota:
Electricity and fuel are needed and these are expensive
Raw materials
Nota:
The raw materials may be rare or expensive, and complex chemical reactions may be needed to make a drug from them
Time taken for development
Nota:
Research and testing take a long time, and a new drug must be licenced for use.
Marketing
Nota:
Healthcare professionals have to be told about the drug and how to use it.
Payback time
The time taken to
regain money spent on
development costs
If the patent expires
earlier than this, the
company may lose a
lot of money on the
drug
A patent lasts up to 20
years and prevents
other companies from
making and selling the
drug
Once it
expires,
anyone is
free to
produce
and sell it
Impurities
The presence of harmful impurities could make people ill
Important to make pharmaceutical drugs as pure as possible
Testing the purity of pharmaceuticals
Nota:
It is tested by measuring its melting or boiling point, as impurities alter the temperature at which a drug melts or boils. The further the temperature is away from the correct one, the less pure the drug is.
It can also be tested by TLC ( Thin Layer Chromatography). The different substances move through the a thin layer of of powder coated onto a glass or plastic plate. Colourless substances show up as spots on the plates when reacted with certain chemicals. These may be fluorescent under ultra violet light, or they may become coloured when heated.