a. what is the effect on the Kc when the temperature of an exothermic reaction is lowered?
b. according to Le Chatelier's principle, how is equilibrium in part a established.
What is the question?
a. When the temperature of an exothermic reaction is lowered, the effect on the equilibrium constant (Kc) depends on the nature of the reaction. In general, decreasing the temperature of an exothermic reaction will cause the equilibrium to shift in the forward direction to compensate for the decrease in heat. This means that more products will be formed, resulting in an increase in the value of Kc.
To understand this concept, you need to know the basic principles of Le Chatelier's principle. According to Le Chatelier's principle, a system at equilibrium will respond to any changes imposed on it in order to maintain equilibrium. In the case of an exothermic reaction with a decrease in temperature, the system will counteract this change by producing more heat. To do so, it favors the forward reaction, which is exothermic, in order to release more heat and restore the equilibrium. As a result, the concentration of products increases, causing an increase in Kc.
b. Le Chatelier's principle states that when a system at equilibrium is subjected to a change, the equilibrium will shift in a direction that tends to counteract the change and restore equilibrium. In the context of part a, when the temperature of an exothermic reaction is lowered, the system will shift in the forward direction to compensate for the decrease in heat.
To establish equilibrium according to Le Chatelier's principle in this case, you can summarize the following steps:
1. Recognize the change: Identify that the temperature of the system has been lowered.
2. Determine the effect: Understand that the exothermic reaction will counteract this change by producing more heat, which can be achieved by favoring the forward reaction.
3. Predict the shift: Since the forward reaction releases heat, the system will shift in the forward direction to increase the production of products and restore equilibrium.
4. Analyze the outcome: As a result, the concentration of products will increase, increasing the value of the equilibrium constant, Kc.
Overall, Le Chatelier's principle helps us understand how changes in different factors, such as temperature, affect the equilibrium of a reaction and how the system responds to maintain stability.