seesaw concept
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seesaw concept
I am confused how the seesaw concept actually work. Is it just multiplying Ka and Kb out then simplifying by crossing out what's similar in both the numerator and denominator?
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Re: seesaw concept
Hi!
The seesaw concept basically says that a strong acid must have a weak conjugate base, and vice versa. We know that Ka times Kb will have to give us Kw, or 10^-14. So if we have a Ka of 10^-2, which indicates a strong acid, we must have a Kb of 10^-12, which indicates a weak conjugate base. When you are solving for a Kb given a Ka, you can certainly cancel out common factors to simplify, but this cancelation itself isn't the seesaw concept - the relationship between the Ka and Kb, and thus the ability of the acid to ionize is what the concept is based on.
Hope this helps!
The seesaw concept basically says that a strong acid must have a weak conjugate base, and vice versa. We know that Ka times Kb will have to give us Kw, or 10^-14. So if we have a Ka of 10^-2, which indicates a strong acid, we must have a Kb of 10^-12, which indicates a weak conjugate base. When you are solving for a Kb given a Ka, you can certainly cancel out common factors to simplify, but this cancelation itself isn't the seesaw concept - the relationship between the Ka and Kb, and thus the ability of the acid to ionize is what the concept is based on.
Hope this helps!
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Re: seesaw concept
Kaylah Nguyen 3B wrote:I am confused how the seesaw concept actually work. Is it just multiplying Ka and Kb out then simplifying by crossing out what's similar in both the numerator and denominator?
the seesaw concept is just stating that if there is a weak acid then there will be a corresponding strong conjugate base and if there is a strong acid there will be a corresponding weak conjugate base
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Re: seesaw concept
The seesaw concept relates back to strengths of acids/bases and their corresponding conjugates. For example, if you had a strong acid, you would have a weak conjugate base. But, if you had a weak acid, you would have a strong conjugate base.
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Re: seesaw concept
To answer your question, we must look at the formula Ka x Kb = Kw, which in numerical terms is, (1.0x10^-7)(1.0x10^-7) = 10^-14. This would mean that if you had a Kb with a value of 1.0x10^-3, then the resulting Ka would have to “balance” this out by having a Ka of 1.0x10^-11 in order to meet the Kw value of 10^-14. That is why it is called the conjugate “seesaw.” I hope this helps!
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Re: seesaw concept
The conjugate seesaw describes a concept where the stronger the acid, the weaker its conjugate base. Similarly, the stronger the base, the weaker its conjugate acid.
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Re: seesaw concept
So the seesaw concept basically states that if there is a weak acid, there is a strong base and vice versa. If you see the equation KaxKb=Kw they will be trying to balance each other out.
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Re: seesaw concept
The conjugate seesaw is the concept that the stronger a weak acid or base is, the weaker its conjugate must be. Intuitively this should make sense as if some acid has a very high Ka and thus has a strong propensity to donate a proton, the equilibrium for the reaction will be strongly favoring the products, so the reverse rxn in which the conjugate base accepts a proton to form the acid, will not occur as often in comparison.
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Re: seesaw concept
The two main ideas I think of for the conjugate seesaw concept are : the stronger the acid, the weaker its conjugate base and the stronger the base, the weaker its conjugate acid. This makes sense as the water constant remains constant/fixed. For example, a strong acid has a relatively high Ka value. Looking at the equation, Kw= Ka x Kb, we know that Kb will have to decrease with an increase in Ka, for Kw to remain constant. With a lower Kb, the conjugate base of this strong acid will be weaker.
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Re: seesaw concept
Adding on to everyone's comments, it's also important to note that the stronger the acid, the weaker its conjugate base. Similarly, the stronger the base, the weaker its conjugate acid.
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