Equilibria Flashcards
Define dynamic in terms of dynamic equilibrium
Forward and backward reactions occur simultaneously
When is equilibrium reached in a chemical reaction?
When rate of forward and backward reactions is the same
What is Le Chatelier’s Principle?
If an external condition is changed, the position of the equilibrium will shift in the direction that will oppose that change
What is the effect of an increase in temperature on the position of equilibrium?
Moves in endothermic direction
What is the effect of a decrease in temperature on the position of equilibrium?
Moves in exothermic direction
What is the effect of an increase in pressure on the position of equilibrium?
Moves towards side with fewer moles of gas
What is the effect of a decrease in pressure on the position of equilibrium?
Moves towards side with more moles of gas
What is the effect of a low temperature on rate of reaction?
Low rate as few molecules have E >= Ea
What is the effect of concentration on position of equilibrium?
Moves to return to original concentrations
What is the effect of a catalyst on the position of equilibrium?
No change - speeds up rate at which equilibrium is reached
Give the conditions for the Haber process
450°C
200 - 1000 atm
Iron catalyst
Give the conditions for forming methanol from CO
400°C
50 atm
Chromium and zinc catalyst
Give the conditions for steam hydration of ethene
300°C
70 atm
Concentrated phosphoric acid catalyst
Give the conditions for the contact process
450°C
1 - 2 atm
V2O5 catalyst
Define the rate constant of a reaction
For reaction
mA + nB ⇌ pC + qD
KC=[C]^p [D]^q / [A]^m [B]^n
