Unit 1: Section 6- Equilibria Flashcards
What are two features of dynamic equilibrium?
- Forward and backward reactions are occurring at
equal rates. - The concentrations of reactants and products
stays constant
How would the reaction be effected if it was ‘to the left’?
if the position of equilibrium favours the reactants then the equilibrium
mixture will contain mostly reactants.
How would the reaction be effected if it was ‘to the right’?
if the position of equilibrium favours the products then the equilibrium
mixture will contain mostly products.
What is Le Chateliers Principles?
Le Chatelier’s principle states that if an external
condition is changed the equilibrium will shift to
oppose the change (and try to reverse it).
How will increasing temperature effect equilibrium?
If temperature is increased the equilibrium will
shift to oppose this and move in the endothermic
direction to try to reduce the temperature by
absorbing heat.
How will decreasing temperature effect equilibrium?
If temperature is decreased the equilibrium will
shift to oppose this and move in the exothermic
direction to try to increase the temperature by
giving out heat.
What is the equation for making ammonia?
N2 + 3H2 reversible reaction 2NH3
How does increasing pressure have an effect on equilibrium?
increasing pressure will cause the equilibrium to shift
towards the side with fewer moles of gas to oppose the
change and thereby reduce the pressure.
How does decreasing pressure have an effect on equilibrium?
Decreasing pressure will cause the equilibrium to shift
towards the side with more moles of gas to oppose the
change and thereby increase the pressure.
What is the equation for the reversible reaction of methanol and what is the enthalpy change?
CO + 2H2 –> CH3OH
exothermic
What effect does a catalyst have on equilibrium?
no effect
speeds up forward and backward reactions by the same amount
however, can speed up the rate that equilibrium can be achieved
Describe and explain the conditions needed for the Haber process
low temp (450) gives good yield, but slow rate: compromise temperature used
high pressure gives good yield and high rate: too high a pressure would lead to high energy costs
Describe and explain the conditions needed for the production of methanol from CO
low temperature gives good yield but slow rate: compromise temp used
high pressures give good yield and high rate: too high a pressure would lead to high energy costs
What is the equation of the hydration of ethene to produce ethanol?
CH2=CH2 (g) + H2O (g) ⇌ CH3CH2OH(l)
Describe and explain the conditions for the production of ethanol
low temp, good yield but slow rate, compromise temperature used
high pressure gives good yeild and high rate: too high pressure could lead to unwanted polymerisation of ethene to polyethene
