Chemistry A-level exam questionWatch
As it is being cooled La Chatliers Principle states that the system would oppose change. Cooling it to 250 means decreasing the temperature and this means the system will oppose the change and move in the forward direction meaning it would go darker. By Compressing it it means they are increasing the pressure. By increasing the pressure, the position of the equilibrium would favour the side with fewer moles which is the I2 therefore it goes purple.
In the reaction, don't both sides have the same number number of gas molecules, so where does the equilibrium shift?
There is no pressure effect in this case; I am assuming you have covered Kc. A simple idea is that the exothermic reaction is favoured, hence forward reaction is prefered (eq. shifts to right).
Hm... Are you sure?
Effect of Pressure- If pressure is increased then equilibrium will shift in the direction where volume is decreased.
That is specific to that reaction.... If anything, gas laws suggest an increase in temperature, so in fact it would shift to the left... Hm....
However increasing the pressure brings particles closer together which results in increasing the concentration of all particles - but this also has no effect on equilibrium position! One might say 'A' could be the answer 'no visible changed' as the equilibrium position is not affected, but it would be wrong:
The purple molecules are concentrated together making the colour more intense.
A horrible trick question that has nothing to do with equilibrium and more of a physical thing that I bet would be no where to found on the syllabus.
I'm not 100% sure of the above, hopefully someone can confirm. I think Hydrafly said something similar