We are going to ask questions for the following reaction according to Le Chatlier's Principle. I will start with a question, the next person should answer it and ask their own question.
CaCO3(s) ⇌ CaO(s) + CO2(g) ∆H = 131.4 kJ
Explain what happens to the value of the equilibrium constant when CaO is added to the reaction at equilibrium.
I believe the equilibrium constant would decrease due to a larger value created in the denominator of the equation k=[CaCO2]/[CaO][CO2]. I used Kahn's video to get an idea of it if anyone is interested http://www.youtube.com/watch?v=4-fEvpVNTlE. My question is more conceptual about why the reaction goes back and fourth till equilibrium is met. If someone could clear up what is going on during the reaction that'd be great!
I thought more about it and decided I have it backwards. The rate constant of the reaction in the forward direction is divided by the rate constant of the reaction in the reverse direction. k=[CaO][CO2]/[CaCO2] meaning that the equilibrium constant, k, will increase with the increase in CaO. I may be wrong, but I think the increase in CaO creates more collisions in the reaction so the rates between CaO and CO2 increase.
Keep in mind that changing the concentrations does NOT change the value of the equilibrium constant. It will change the position of the equilibrium as long as it is not a solid.
To answer your question: the reaction goes back and forth until equilibrium is met because entropy (randomness) wants to be achieved. The reaction occurs because of the collision theory, and the orientation of the molecules hitting each other that cause the reaction to occur eventually bringing it to equilibrium.
What is the equilibrium constant expression for the above reaction Ms. Nguyen gave? (hint: pay attention to the states of matter)
The equilibrium constant will be inversed by reversing the equation and since the reaction when reversed is exothermic adding heat will decrease the equilibrium constant
NO2(g) + NO(g) <----> NO2(g) + ClNO(g) 1 mole of each substance exists in a 1 liter @ 52 degrees c what is the Kp?
I believe the equilibrium constant would decrease due to a larger value created in the denominator of the equation k=[CaCO2]/[CaO][CO2]. I used Kahn's video to get an idea of it if anyone is interested http://www.youtube.com/watch?v=4-fEvpVNTlE. My question is more conceptual about why the reaction goes back and fourth till equilibrium is met. If someone could clear up what is going on during the reaction that'd be great!
ReplyDeleteI thought more about it and decided I have it backwards. The rate constant of the reaction in the forward direction is divided by the rate constant of the reaction in the reverse direction. k=[CaO][CO2]/[CaCO2] meaning that the equilibrium constant, k, will increase with the increase in CaO. I may be wrong, but I think the increase in CaO creates more collisions in the reaction so the rates between CaO and CO2 increase.
ReplyDeleteKeep in mind that changing the concentrations does NOT change the value of the equilibrium constant. It will change the position of the equilibrium as long as it is not a solid.
DeleteTo answer your question: the reaction goes back and forth until equilibrium is met because entropy (randomness) wants to be achieved. The reaction occurs because of the collision theory, and the orientation of the molecules hitting each other that cause the reaction to occur eventually bringing it to equilibrium.
ReplyDeleteWhat is the equilibrium constant expression for the above reaction Ms. Nguyen gave? (hint: pay attention to the states of matter)
Easy! Kc = [CO2]/1, [CaO] and [CaCO2] are both solids and don't factor into the equation.
ReplyDeleteIf Mrs Nguyens equation was reversed, what effect would it have on the equilibrium constant if heat was added to the reaction?
The equilibrium constant will be inversed by reversing the equation and since the reaction when reversed is exothermic adding heat will decrease the equilibrium constant
ReplyDeleteNO2(g) + NO(g) <----> NO2(g) + ClNO(g)
1 mole of each substance exists in a 1 liter @ 52 degrees c what is the Kp?
Kc = 1*1/(1*1) = 1 and since same moles of gaseous reactants and products then Kp will equal Kc.
DeleteGuy, nicely thought through in response to Dustin's question. Let's add to your question that those are equilibrium amounts.
ReplyDeleteThanks for your responses!
ReplyDelete