Explaining How Temperature Change Affects Chemical Equilibrium

In summary, LeChatelier's principle states that a chemical system at equilibrium will shift to counteract any changes in concentration, temperature, volume, or partial pressure. In an exothermic reaction, an increase in temperature will shift the equilibrium to the left, and a decrease in temperature will shift it to the right. The opposite is true for endothermic reactions. This principle can be applied to predict how equilibrium systems will respond to changes in conditions.
  • #1
Sirsh
267
10
Hey all the people reading this, Just wondering if anyone can explain how a equilibrium system changes with a increase/decrease in temperature occurs.


I've been taught that: If my reaction is exothermic i.e. reactants -> products + energy; and i am going to decrease temperature it would be said that the energy acts as a 'product' therefore to counteract this the system would have to convert the loss of energy to enthalpy or something.

could someone please help me with this!

Thank you! - sirsh.
 
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  • #2
What you refer to is LeChatelier's principle. Exotermic reaction equilibrium shifts to the left when temperature increases, endotermic reaction equilibrium shifts to the right when temperature increases.

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methods
 
  • #3
So. temperature is increased: Reactants -> products + energy then we will see a shift to the left. if the temp for this exothermic reaction is decreased the reaction will shift to the right? and then the same for endothermic in the reaction where temperature is increased: reactants + energy -> products, when the temp increases equilibrium shifts to the right and when decreases it shifts to the left. can you please explain to me why? if that's not too much to ask. thanks alot!
 
  • #4
http://en.wikipedia.org/wiki/Le_chatelier's_principle

If a chemical system at equilibrium experiences a change in concentration, temperature, volume, or partial pressure, then the equilibrium shifts to counteract the imposed change and a new equilibrium is established.

In the exothermic reaction - when temperature goes up - shifting equilibrium to the left lowers temperature of the reaction mixture. That a direct application of principle. Similar thinking for endothermic reaction and increased temp.

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  • #5


Hello sirsh,

Thank you for your question. Temperature change can have a significant impact on chemical equilibrium. In order to understand this, we must first understand what chemical equilibrium is.

Chemical equilibrium is a state in which the concentrations of reactants and products in a reversible chemical reaction remain constant over time. This means that the rate of the forward reaction is equal to the rate of the reverse reaction. In this state, the system is said to be at equilibrium.

Now, when we change the temperature of a system at equilibrium, it affects the rates of the forward and reverse reactions. This is because temperature is directly related to the kinetic energy of the molecules involved in the reaction. An increase in temperature will result in an increase in the kinetic energy of the molecules, leading to an increase in the rate of both the forward and reverse reactions.

In an exothermic reaction, heat is released as a product. So, when we decrease the temperature, the reaction will shift in the direction that produces more heat, in order to compensate for the loss of energy. This means that the equilibrium will shift towards the reactants, resulting in an increase in their concentration. Conversely, when we increase the temperature, the reaction will shift in the direction that consumes heat, resulting in an increase in the concentration of products.

To summarize, a change in temperature affects the equilibrium by changing the rates of the forward and reverse reactions, which in turn affects the concentrations of reactants and products. I hope this helps to clarify the concept for you. Let me know if you have any further questions.
 

1. What is chemical equilibrium?

Chemical equilibrium is a state in which the forward and reverse reactions of a chemical reaction occur at equal rates. This means that the concentration of reactants and products remain constant over time.

2. How does temperature change affect chemical equilibrium?

Temperature change can affect chemical equilibrium by shifting the position of the equilibrium. For an endothermic reaction, an increase in temperature will shift the equilibrium towards the products, while for an exothermic reaction, an increase in temperature will shift the equilibrium towards the reactants. This is because temperature is directly related to the energy of the reactants and products, which can influence the rate of the forward and reverse reactions.

3. How does Le Chatelier's principle apply to temperature change and chemical equilibrium?

Le Chatelier's principle states that when a system at equilibrium is subjected to a change, the system will respond in a way that minimizes the effect of the change. In the case of temperature change, this means that the equilibrium will shift in the direction that absorbs or releases heat to maintain a constant temperature.

4. How does temperature change affect the equilibrium constant?

The equilibrium constant (K) is a ratio of the concentrations of products to reactants at equilibrium. A change in temperature can affect the equilibrium constant by altering the relative concentrations of products and reactants. This is because the equilibrium constant is determined by the standard free energy change, which is temperature-dependent.

5. Can temperature change break a chemical equilibrium?

No, temperature change cannot break a chemical equilibrium. It can only shift the position of the equilibrium. The equilibrium will always be re-established in order to maintain the constant concentration of reactants and products. However, a large enough temperature change can cause the reaction to go to completion in order to reach a new equilibrium position.

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