Topic 6- Equilibria Part 2 Flashcards
How can ethanol be produced and describe?
What are the three conditions that this reaction is carried out at?
What does lower temperature favour?
What does this mean happens?
What does lower temperatures mean?
What temperature is used and why?
What does higher pressure do to the equilibrium?
What does this do to this reaction?
What does high pressures also do?
What pressure is used in the making of ethanol?
What two reasons are very high pressures expensive to produce?
What two reasons is this pressure used?
Via a reversible exothermic reaction between ethene and steam
Carried out at pressures of 60-70 atmospheres and a temperature of 300oC with a catalyst of phosphoric acid
The forward reaction
More ethene and steam is converted to ethanol- you get a better yield
A slower rate of reaction
300oC is a compromise between a reasonable yield and a faster reaction
Higher pressure shifts the equilibrium to the side with fewer molecules
Here it favours the forward reaction
Increases the rate of reaction too
A pressure of 60-70 atmospheres is used
You need really strong pipes and containers to withstand high pressures
It’s a compromise- it gives a reasonable yield for the lowest possible cost.
What do the following conditions do to an exothermic reaction:
A low temperature
A high temperature
What does a high pressure mean for gaseous reactions?
But what are two consequences of this?
What is a low yield of expensive reactants improved by?
Means high yield and low rate
Means low yield and high rate
A high pressure means high rate
Expensive equipment and expensive to pump gas up to high pressure
Recycling the unreacted reactants.
