When to use Q versus K [ENDORSED]
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Re: When to use Q versus K
^ Yes, when the Gibb's free energy of the reactants is not equal to the Gibb's free energy of the products, you would use Q because it is not at equilibrium.
You would use K when the reaction is at equilibrium because it is a standard energy change of a reaction.
You would use K when the reaction is at equilibrium because it is a standard energy change of a reaction.
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Re: When to use Q versus K
Q is the reaction quotient while K is the equilibrium constant. You use K at equilibrium or when delta G is equal to 0. You use Q when delta G is not equal to 0.
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Re: When to use Q versus K
Q is the reaction quotient and expresses the relative ratio of products to reactants at a given instant. Whereas, K is the equilibrium constant and expresses the ratio of products to reactants at equilibrium (when delta G=0).
Use ΔG= ∆G°+ RTlnQ when the system is not at equilibrium.
Use ΔG= ∆G°+ RTlnK when the system is at equilibrium.
Use ΔG= ∆G°+ RTlnQ when the system is not at equilibrium.
Use ΔG= ∆G°+ RTlnK when the system is at equilibrium.
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Re: When to use Q versus K
You use Q when the reaction is not at equilibrium and use K when the reaction is at equilibrium.
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Re: When to use Q versus K [ENDORSED]
K is the ratio of concentration of products to concentration of reactants when the reaction is at equilibrium. Q is the ratio when the reaction is not at equilibrium. Therefore, you would use K when at equilibrium, and Q when not at equilibrium.
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