Le Châtelier’s Principle - equilibrium position changed when outside force disturbs the system
- affected by concentration, temperature, pressure
- change in reactant/product concentration >> reaction shifts to use up the added substance
- lower volume, higher pressure >> reaction shifts to produce less moles of gas
- higher volume, lower pressure >> reaction shifts to produce more moles of gas
- higher temperature >> reaction shifts to use up extra energy (depends on whether reaction is exothermic/endothermic)
- catalysts - only changes how fast equilibrium is achieved, not characteristics of equilibrium itself
Describe the effect on CaCO3(s) >> CaO(s) + CO2(g) when:
- pressure increased
- shifts so that less gas is produced
- shifts left
- volume increased
- same as decreasing the pressure
- shifts right to produce more gas
- adding CaCO3
- no effect, it's a solid
For reaction PCl5(g) >> PCl3(g) + Cl2(g), K = 0.015 and DH = -375. What happens when Cl2 is removed?
- disregard K or DH
- they have nothing to do w/ the problem
- reaction shifts right to produce more Cl2
For endothermic equation N2(g) + O2(g) >> 2NO(g), K = 4.0 x 10-4. What happens when pressure is increased?
- again, disregard K
- same amount of moles of gas on both sides of equation
- reaction doesn't shift to either side
For endothermic equation N2(g) + O2(g) >> 2NO(g), K = 4.0 x 10-4. What happens when temperatre is increased?
- N2(g) + O2(g) + energy >> 2NO(g)
- adding temperature >> adding energy
- reaction shifts right to use up energy
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