For the water–gas shift reaction
CO1g2 + H2O1g2 ∆ CO21g2 + H21g2...

Question

For the water–gas shift reaction 
CO1g2 + H2O1g2 ∆ CO21g2 + H21g2, ΔH° = - 41.2 kJ 
does the amount of H2 in an equilibrium mixture increase or decrease when the temperature is increased? How does Kc change when the temperature is decreased? Justify your answers using Le Châtelier’s principle.

Accepted Answer

Hello everyone today. We have the following question. Consider the following equilibrium reaction. How will or a portion A says, how will the concentration of nitric oxide change when the temperature of the system is lowered, B says, how will the equilibrium constant change when the temperature of the system is increased? Explain your answer using last year as principal. So for our A. We have that our entropy change. Our change in entropy is going to be positive or plus 47.4 kg jewels. The fact that it is positive indicates that it is an endo thermic reaction. And so heat is a reactant. So of course from our original equation, we're going to have our chlorine gas, we're gonna add in heat and it is going to give us this following reaction here. So it was stated that the temperature of the system was lowered. So if we decrease our temperature, the reaction will shift to the left and that is due to last year's principle that when there is a disturbance in the system, the system will work to correct it. So lowering the temperature means that we need to create more heat and so it will shift in the direction that the heat originally was. So as a result of this, we can conclude that our nitric oxide will decrease when our when we increase the temperature because the reaction is endo thermic. And so this is the first part of our question. No, for B we need to find what our Casey or equilibrium constant would be and so our equilibrium constant is equal to the products over our reactant. And so that is going to translate as we're going to put our first product in brackets nitric oxide there. Now it does have a two in front of it so that nitric oxide is going to become the exponent of two. We didn't have roaming chloride. So we're going to put that in the brackets next to it and also has A coefficient of two. So what we're gonna do is we're gonna put that to as an expo in it. So that's it for our products for our reactant. We have our nitrous bromide and or B. R. And we do have that coefficient. So we'll have that explained to and then we have chloride gas as our second one. So in this instance we are increasing our temperature and when we increase our temperature, the reaction shifts to the right as a result our K. C. Will increase. And while our Casey increase while we're generating more products. So these numbers in the numerator here will increase. Giving us an overall larger value. And so this is going to be the second part of our answer. If we look at our answer choices, we have to find which one matches up with that. That's gonna be answer choice. D nitric oxide will decrease when the temperature is increased because the reaction is an author Mick and then our case here equilibrium constant will increase because the concentration of the reactant will increase and the concentration of the products will decrease when the temperature is increased. And so with that we have answered the question overall. I hope this helped, and until next time.

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