3.1 Getting the most from reactants Flashcards
industrial processes
Industrial processes are designed to maximise profit and minimise the impact on the environment.
Factors influencing industrial process design
- availability, sustainability and cost of feedstock(s)
- opportunities for recycling
- energy requirements
- marketability of by-products
- product yield
Environmental considerations
- minimising waste
- avoiding the use or production of toxic substances
- designing products which will biodegrade if appropriate
molar volume
The molar volume (litres mol-1) is the volume occupied by one mole of any gas at a certain temperature and pressure. The molar volume is the same for all gases at the same temperature and pressure.
what is percentage yield and atom economy a measure of?
The efficiency with which reactants are converted into the desired product is measured in terms of the percentage yield and atom economy.
how to ensure that a costly reactant is converted into product?
In order to ensure that a costly reactant is converted into product, an excess of the less expensive reactant(s) can be used.
Theoretical yield
the quantity of desired product obtained, assuming full conversion of the limiting reagent
Actual yield
the quantity of the desired product formed under the prevailing reaction conditions.
percentage yield
the percentage yield provides a measure of the degree to which the limiting reagent is converted into the desired product.
percentage yield equation
actual yield over theoretical yield x 100
atom econonmy
measures the proportion of the total mass of all starting materials converted into the desired product in the balanced equation.
atom economy equation
mass fo desired product over total mass of reactants x 100
reactions which have a high percentage yield
may have a low atom economy value if large quantities of by-products are formed.
