QD3 Midterm

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QD3 Midterm

Postby 305421980 » Fri Mar 13, 2020 10:00 pm

I know this question isn't about electrochemical, but the only acid and base section I could find was for 14A.
Somehow I got this question right on the midterm but don't know why or how.
It asks:
At pH 6 what is the net charge for acetic acid, CH3COOH (pKa=4.75)?

What is the concept behind this?

MingdaH 3B
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Re: QD3 Midterm

Postby MingdaH 3B » Fri Mar 13, 2020 11:29 pm

Since pH is higher than the pKa, the acid will dissociate into its conjugate base and H+, and so its conjugate base will have a charge of -1.

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Re: QD3 Midterm

Postby KnarGeghamyan1B » Sat Mar 14, 2020 1:36 am

Why would it be -1 exactly?

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Re: QD3 Midterm

Postby jisulee1C » Sat Mar 14, 2020 8:01 am

At the pH of 6 you are assuming that the acetic acid dissolves into a higher concentration of it's conjugate base CHCH3COO- because the pKa (of acetic acid) =4.75 and the conjugate acid has a change of -1.

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Re: QD3 Midterm

Postby 205154661_Dis2J » Sat Mar 14, 2020 4:03 pm

You are assuming that acetic acid dissolved into CHCH3COO- and H+ due to the pH of 6.

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Re: QD3 Midterm

Postby 005206171 » Sat Mar 14, 2020 7:41 pm

Acetic acid will lose its proton/H+ because it’s an acid. Its conjugate base is CH3COO which makes its charge -1

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