1B1 Equilibria Flashcards
Define dynamic equilibrium?
where the concentrations of all substances are
constant and the rate of the forward reaction equals the rate of the reverse reaction.
Define Le Chatelier’s
Principle(LCP)?
If a system is in equilibrium it will try to oppose any change made to it
Exothermic and Endothermic
Exothermic releases energy, ∆H negative
Endothermic absorbs energy, ∆H positive
Useful thing to remember for temperature in LCP
ALL THE POSITIVES GO TOGETHER i.e. if
you raise the temperature of an endothermic reaction you will increase the yield
What is effect of enzymes on equilibrium?
no effect on the equilibrium position
forward reaction and the backward reactions are speeded up equally
State the conditions used usually for haber process?
50MPa - not dangerous
500C - fast enough
Fe catalyst
How does continuous haber process happens?
Cooling allows ammonia can be separated out
So reactants can be recycled
State the conditions used usually for contact press?
200 Kpa - 98 percent already, so this is safe
500 C - fast enough
V2O5 catalyst
State the conditions used usually for hydration of ethene?
7MPa
300 C
H3PO4
What is equilibrium constant, Kc?
measure of the balance between reactants and products
measure only solutions
Kc properties?
it’s unique for its reaction
change with temperature only
Equation for Kc if aP(aq) + bQ(aq) ⇌ cR(aq) + dS(aq) ?
Kc = [R]^c [S]^d / [P]^a [Q]^b
[] - concentration in mol dm^-3
use this to define Kc
