P1: 6 Equilibria Flashcards
What are the features of a reversible reaction at equilibrium?
Forward and reverse reactions proceed at equal rates.
The concentrations of reactants and products remain constant.
What is Le Chatelier’s principle?
If a closed system at equilibrium undergoes a change in conditions, the equilibrium shifts in the direction to oppose the change.
What effect does a catalyst have on the position of equilibrium?
No effect because it speeds up the rates of both reactions equally.
What effect does increasing the temperature have on the position of equilibrium?
Equilibrium shifts in the endothermic direction to oppose the increase in temperature.
What effect does increasing the concentration have on the position of equilibrium?
Equilibrium shifts to the other side to oppose the increase in concentration.
What effect does increasing the pressure have on the position of equilibrium?
Equilibrium shifts to the side with fewer moles to oppose the increase in pressure.
Why might a compromise temperature and pressure be used in industry?
A lower temperature might increase equilibrium yield but the rate of reaction is too slow so a higher temperature is used to increase the rate of reaction.
A higher pressure might increase equilibrium yield but it’s too expensive to work at higher pressures so a lower pressure is used.
What is the equation for Kc?
Kc = product of molar concentrations of products / product of molar concentrations of reactants
What is molar concentration represented by?
[X]
What is Kc affected by?
Temperature only, not changes in concentration nor the addition of a catalyst.
For an exothermic reaction what does increasing the temperature do to Kc?
Kc decreases.
For an endothermic reaction what does increasing the temperature do to Kc?
Kc increases.
