Reaction Direction
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Reaction Direction
How do we determine is the reaction is "left" or "right". And does the direction of the reaction matter if it is composition or decomposition?
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Re: Reaction Direction
The left and right portions are arbitrary, as, given a reversible reaction, you could switch both sides and the left directional reaction would now be the new right directional compound
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Re: Reaction Direction
You determine it by comparing the equilibrium constant (K) with the reaction quotient (Q). If Q is less than K, then there are less products so the reaction is going to the right. If Q is greater than K, then there are more products so the reaction is going to the left. In this case, it doesn't matter what type of reaction it is.
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Re: Reaction Direction
If Q>K then the reaction moves to the left because the concentration of products is greater than the concentration of reactants so the reaction would move towards the side of the reactants to reach equilibrium. If Q<K, then the reaction moves to the right because the concentration of reactants is greater than the concentration of products so the reaction would move towards the side of the products to reach equilibrium.
Re: Reaction Direction
I know that K represents the equilibrium constant, but what does Q represent in this situation?
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Re: Reaction Direction
005384106 wrote:I know that K represents the equilibrium constant, but what does Q represent in this situation?
In this situation, Q would represent the state of the reaction at a point where equilibrium has not been reached yet. This is why they are asking about which direction the reaction will occur ("left" or "right") because the Q value will determine it.
Re: Reaction Direction
I am confused with the equilibrium ratio when using molarity values compared to the equilibrium ratio using partial pressure. Can someone please explain this to me. Thank you
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Re: Reaction Direction
When dealing with equilibrium, the reactions are typically reversible meaning that it could be left to right or the other way around
Re: Reaction Direction
Morgan Carrington 2H wrote:005384106 wrote:I know that K represents the equilibrium constant, but what does Q represent in this situation?
In this situation, Q would represent the state of the reaction at a point where equilibrium has not been reached yet. This is why they are asking about which direction the reaction will occur ("left" or "right") because the Q value will determine it.
How will I know whether a reaction will occur left or right based on Q?
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Re: Reaction Direction
005384106 wrote:Morgan Carrington 2H wrote:005384106 wrote:I know that K represents the equilibrium constant, but what does Q represent in this situation?
In this situation, Q would represent the state of the reaction at a point where equilibrium has not been reached yet. This is why they are asking about which direction the reaction will occur ("left" or "right") because the Q value will determine it.
How will I know whether a reaction will occur left or right based on Q?
If Q>K the reaction will move to the left because the concentration of products is greater than the concentration of reactants. If Q<K the reaction will move to the right because the concentration of reactants is greater than the concentration of products.The reaction will move towards the direction necessary to reach equilibrium.
Re: Reaction Direction
What is the reaction quotient, Q? Can you determine it by concentration values or K?
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Re: Reaction Direction
One way to determine if the reaction will proceed right or left is by comparing to equilibrium value to the reaction quotient value. If your reaction quotient (Q) is less than K than your reactants will continue to react and your reaction will proceed to the right towards the products and vice versa, if Q is greater than K then the reaction will favor going left towards the reactants.
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Re: Reaction Direction
You can determine them using Q and K, for Q>K, the reaction favors reactants and moves left, for Q<K, it favors products and proceeds to the right.
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Re: Reaction Direction
It was mentioned in the modules to compare Q and K. Where Q is the reaction quotient and K is the equilibrium constant.
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Re: Reaction Direction
If the K value is a huge number, then it is towards products but if it is a small number then it's towards reactants.
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Re: Reaction Direction
Hi,
In order to determine the predominant direction of a reaction, it depends on how you phrase it. Whether you are talking about the relative magnitudes of the K value (1) or a response in doing something to perturb the system (2). Note, whether the reaction is a decomposition or synthesis reaction doesn't necessarily tell you much about direction.
(1) If K is large, it favors the products while if K is small, it favors the reactants.
(2) If you do something to disrupt the system (I've listened some scenarios below), you must use Le Chatelier's Principle to determine the direction.
- Increasing/Decreasing the concentrations of reactants/products
- Increasing/Decreasing the volume
- Increasing/Decreasing the partial pressures of reactants/products
- Increasing/Decreasing the temperature
Hope this helps! :)
In order to determine the predominant direction of a reaction, it depends on how you phrase it. Whether you are talking about the relative magnitudes of the K value (1) or a response in doing something to perturb the system (2). Note, whether the reaction is a decomposition or synthesis reaction doesn't necessarily tell you much about direction.
(1) If K is large, it favors the products while if K is small, it favors the reactants.
(2) If you do something to disrupt the system (I've listened some scenarios below), you must use Le Chatelier's Principle to determine the direction.
- Increasing/Decreasing the concentrations of reactants/products
- Increasing/Decreasing the volume
- Increasing/Decreasing the partial pressures of reactants/products
- Increasing/Decreasing the temperature
Hope this helps! :)
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Re: Reaction Direction
It depends on what is provided. If K>1 the products are favored. If K<1, the reactants are favored. If the reaction quotient Q is provided then you use both Q and K to determine the direction. If Q<K, it shifts right and reactants are favored. If Q>K, it shifts left and products are favored.
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