November 25, 2024, 11:52:53 PM
Forum Rules: Read This Before Posting


Topic: Acid dissociation constant  (Read 2847 times)

0 Members and 1 Guest are viewing this topic.

Offline Danial

  • Regular Member
  • ***
  • Posts: 30
  • Mole Snacks: +0/-0
Acid dissociation constant
« on: September 11, 2010, 02:04:26 AM »
We determined the acid dissociation constant of acetic acid.
But the temperature we measured our conductivities at was 24 degrees Celsius, would this cause the acid dissociation constant to increase? because our results are higher than the literature value

do conductivity meters take the temperature into account and calculate the conductivity at 25 degrees?

also, if you have two sets of results, which have been plotted to form a linear relationship with non bias residuals.
And find that both results ultimately have the same error associated to them, would that account for a systematic error?
do non bias residuals just mean the sample is good?
« Last Edit: September 11, 2010, 02:28:19 AM by Danial »

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27864
  • Mole Snacks: +1813/-412
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Acid dissociation constant
« Reply #1 on: September 11, 2010, 03:35:53 AM »
the temperature we measured our conductivities at was 24 degrees Celsius, would this cause the acid dissociation constant to increase?

Yes, but the difference would be negligible, Ka gets higher about 1.0005 times per degree.

Quote
do conductivity meters take the temperature into account and calculate the conductivity at 25 degrees?

Depends on the meter. Can be.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline Danial

  • Regular Member
  • ***
  • Posts: 30
  • Mole Snacks: +0/-0
Re: Acid dissociation constant
« Reply #2 on: September 11, 2010, 04:15:55 AM »
oh thanks Borek,
The last part of my discussion i want to talk about the residuals of the plot
but i also stated that the errors of each measurement are similar which suggests a systematic error
if the residuals are randomly spread showing a non bias sample, can i still say its a systematic error?
cause im kind of confused about all that stuff

like i thought, its a non bias sample, so its a good sample, but the errors are consistent, so they're systematic?

Sponsored Links