Industrial chemical reactions Flashcards
what happens when a reaction reached dynamic equilibrium? (3)
the forward and backward reactions are still happening
the forward and backward reactions have the same rate of reaction
the concentrations of all the reacting substances remain constant (they do not change)
what will happen to the position of equilibrium if the Pressure increased?
+ to the time taken?
position moves towards the fewest molecules of gas
decreased
what will happen to the position of equilibrium if the Concentration increased?
+ to the time taken?
Equilibrium position moves away from that reactant
decreased
what will happen to the position of equilibrium if the Temperature increased?
+ to the time taken?
Equilibrium position moves in the direction of the endothermic reaction
decreased
what will happen to the position of equilibrium if the Catalyst added?
+ to the time taken?
No change in equilibrium position
decreased
what are the conditions used related to the availability and cost of? (2)
raw materials
energy supplies
what are the two ways of obtaining hydrogen?
gas and steam
electrolysis of water
which raw material and energy supplies are needed for ‘gas and steam’
Natural gas is a non-renewable resource
Strong heating using natural gas, coal or fuels from crude oil
which raw material and energy supplies are needed for ‘Electrolysis of water’?
Water is readily available from rivers, lakes and oceans
Electricity can be generated using renewable resources
why are specific reaction conditions used for chemical reasons in industrial processes?
to obtain an acceptable yield of product in an acceptable time.
why is a compromise of 450 degrees used in the haber process? (5)
-low temperatures = favours haber process, shift equilibrium position to right but is slow
-increasing temperature = increases rate of reaction
-shifts position towards the direction of endothermic (left in haber process)
low enough to achieve an acceptable yield
high enough to do this in an acceptable time
why is a compromise of 200 atmospheres used in the haber process? (5)
-increased pressure moves eqb position towards fewest molecules (right in haber process)
-expensive to achieve very high pressures.
-Stronger equipment is needed, and more energy is needed to compress the gases.
low enough to keep costs down
high enough to achieve an acceptable yield
why is an iron catalyst used in the haber process? (2)
-helps to achieve an acceptable yield in an acceptable time.
-allows a lower temperature to be used, which saves energy but also increases the yield of the reaction.
what does the reaction pathway depend on? (5)
UREAP
percentage yield
atom economy
rate of reaction
equilibrium position
usefulness of by-products
