pH of weak acid and base

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Kayley Steele 3D
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pH of weak acid and base

Postby Kayley Steele 3D » Mon Jan 17, 2022 9:19 pm

Can someone explain how to calculate the percent protonated of a weak base once you solved for x in the ICE box?

Carina H - 2G
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Re: pH of weak acid and base

Postby Carina H - 2G » Mon Jan 17, 2022 9:39 pm

Hi!

Once you solve for X in an ice chart, X will be the value of the [OH-] concentration, and thus the conjugate acid concentration as well. Use the value of X and divide by the initial concentration of the reactant, then multiply by 100 to get the percent protonation. Hope this helps!

Rhea Desai 1A
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Re: pH of weak acid and base

Postby Rhea Desai 1A » Mon Jan 17, 2022 11:01 pm

The percent protonated means how much of the base gained an hydrogen ion. So, to find this we have to take the conjugate acid concentration at equilibrium (which is usually X) and divide it by the initial amount of the weak base * 100. By doing this, you are finding what percentage of the weak base actually reacted with water to gain a H+ ion, which is called protonation.

SuryaDham 3E
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Re: pH of weak acid and base

Postby SuryaDham 3E » Mon Jan 17, 2022 11:29 pm

you take x and put it over the initial concentration of the acid and multiply by 100

Kimia Rategh 2A
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Re: pH of weak acid and base

Postby Kimia Rategh 2A » Mon Jan 17, 2022 11:58 pm

Hi! When trying to find the percent protonated of a weak base (or acid), you are basically trying to find how much of the weak base dissociated, or reacted with water throughout the reaction. Therefore, you would use the ICE Box to find the equilibrium concentrations of each of the species in the reaction. You normally do this by finding an x. Then, you would take that x value and divide it by the initial concentration of the weak base. To find the percentage you would then just multiply by 100.

Hope this helps!

Kaira Shibata 1E
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Re: pH of weak acid and base

Postby Kaira Shibata 1E » Tue Jan 18, 2022 4:05 pm

Once you have x, plug it back in to solve for the concentration of H+. Once you have that, you take the -log[H+] and that gives you the pH.

Brandon Padilla 2L
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Re: pH of weak acid and base

Postby Brandon Padilla 2L » Tue Jan 18, 2022 4:31 pm

Once you have solved for x, divide it by the initial concentration of the reactant and multiply by 100 to get the percent protonation.

Thailer Phorn 1C
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Re: pH of weak acid and base

Postby Thailer Phorn 1C » Tue Jan 18, 2022 6:52 pm

You divide X by the initial concentration of the reactant and then multiply by 100 to calculate the percent protonation.

Lawrence Tran 2H
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Re: pH of weak acid and base

Postby Lawrence Tran 2H » Tue Jan 18, 2022 10:06 pm

Since x should be the [OH-] concentration during protonation, you can divide this value by the initial concentration and multiply by 100% to find the percent protonation.

Crystal Ma 2J
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Re: pH of weak acid and base

Postby Crystal Ma 2J » Tue Jan 18, 2022 11:32 pm

x/initial concentration times 100%

Ashrita Singh 2F
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Joined: Fri Sep 24, 2021 6:33 am

Re: pH of weak acid and base

Postby Ashrita Singh 2F » Wed Jan 19, 2022 3:43 pm

Use the equation (x/initial) x 100%.


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