Equilibria Flashcards
Define equilibrium mixture
All components in a reversible reaction remain constant
What are the conditions for equilibrium?
. Closed system
. Equilibrium is dynamic= rates of two opposing processes are the same
. The macroscopic properties wont change e.g density, conc, colour, pressure
What happnes when the proportion of products is increased?
Equilibrium moves to the right or forward
What happens when proportion of reacrants is increased?
Equilibrium moves to left or backward
What is Le Châtelier’s principle?
If a system at equilibrium is disturbed, the equilibrium moves in the direction that tends to reduce the disturbance
What does Le Châtelier’s principle say happens if a reactant concentration is increased?
A + B C + D
If A is increased the system would react to reduce it. It would use up more B and produce more C and D so equilibrium moves to the right.
How does pressure affect reactions with gasses?
Increasing pressure the system will move to reduce the pressure so would move to the left. If you decrease the pressure the equilibrium will move to the right.
How does changing the pressure affect equilibrium?
If its exothermic one way it will be endothermic the other. If temperature is increased the system will move to cool it down so move in the direction that absorbs heat, if its exothermic going forward it would move to the left and the opposite for decreased temperature.
How do catalysts affect equilibrium?
Catalysts have no effect on the position of equilibrium but they allow it to be reached faster
How do u calculate the units for Kc?
2A + B 2C
Kc = [C]² / [A]²[B]
( moldm‐³ )² / ( moldm-³)² (moldm-³) = mol-¹ dm³
What is the effect of change in temperature on Kc?
If reaction is exothermic and temperature increases Kc decreases and if temperature decreases Kc increases.
If reaction is endothermic and temperature decreases Kc decreases if temperature increases then Kc increases.
How do you calculate partial pressure?
Mole fraction X total pressure
How do you calculate mole fraction?
Moles of x / total moles
Write an expression for Kp for this reaction
A + 2B Y + Z
Kp = pY+pZ / pA+p²B
