QD3 Midterm

Moderators: Chem_Mod, Chem_Admin

305421980
Posts: 101
Joined: Sat Sep 07, 2019 12:16 am

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
Posts: 133
Joined: Thu Jul 11, 2019 12:17 am

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.

KnarGeghamyan1B
Posts: 102
Joined: Fri Aug 09, 2019 12:15 am

Re: QD3 Midterm

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

Why would it be -1 exactly?

jisulee1C
Posts: 149
Joined: Thu Jul 25, 2019 12:17 am

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.

205154661_Dis2J
Posts: 109
Joined: Wed Sep 18, 2019 12:21 am

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.

005206171
Posts: 107
Joined: Wed Sep 18, 2019 12:20 am

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


Return to “Balancing Redox Reactions”

Who is online

Users browsing this forum: No registered users and 2 guests