Equilibria Flashcards
What is the definition of Dynamic equilibrium?
when the concentration of reactants and products remain constant because both the forward and backwards reaction are proceeding at the same rate.
What is Le Chatelier’s Principle?
Le Chatelier’s Principle: when a change is applied to a system in dynamic equilibrium, the equilibrium moves in the direction to oppose the effect of the change.
What conditions affect the equilibrium of a reaction?
Concentration
Temperature
Pressure
Catalyst
How does increasing the temperature affect the position of equlibrium?
moves equilibrium in the endothermic direction in order to reduce the temperature again.
How does decreasing the temperature affect the position of equilibrium?
moves equilibrium in the exothermic direction in order to increase temperature again.
How does increasing concentration affect the position of equilibrium?
reactant moves equilibrium to the side of the products to reduce concentration again.
How does decreasing concentration affect the position of equilibrium?
products move equilibrium to the side of the reactants to increase concentration again.
How does increasing pressure affect the position of equilibrium?
moves equilibrium to the side with the fewest moles to reduce the pressure again.
How does decreasing pressure affect the position of equilibrium?
moves equilibrium to the side with the most molecules to increase pressure again.
When does pressure not affect the position of equilibrium?
when there is an equal number of moles on both sides of the reaction.
What affect does a catalyst have on the position of reaction?
does not change equilibrium.
-increase rate of reaching equilibrium
-allow lower temps and lower pressures to be used
what three things are considered for equilibria: reactions in industry?
-yield of the product
-rate of reaction
-cost of maintaining the reaction
conditions
explain the equilibrium reactions in industry of Ammonia.
Equation:
N2(g) + 3H2(g) –(reversible) 2NH3
Conditions:
450 (Celsius)
200 atm
iron catalyst
Why compromised conditions:
-high pressure favours NH3
yield of 15%
increased pressure favours products (con: expensive)
Uses:
fertilizers
drugs
dyes
nylon
explain the equilibrium reactions in industry of Ethanol.
Equation:
C2H4(g) -(reversible with steam)- C2H5OH
Conditions:
300 (Celsius)
70 atm
phosphoric catalyst
Why compromised conditions:
- high temp increases rate of reaction
-Yield 5%: however the ethene and steam can be recycled
-too much steam can risk dilution of ethene
Uses:
Alcohol
drugs
fuel
detergent
explain the equilibrium reaction in industry for methanol.
Equation:
CO(g)+2H2(g) -reversible- CH3OH(g)
conditions:
230 (Celsius)
100 atm
copper catalyst
why compromised conditions:
temp has to be high enough for reaction to occur nut low enough for a plausible yield
high pressure- high yield of methanol
uses:
chemical feedstock
(material to make other chemicals)
manufacture plastics
fuel
