sirsomething
Harmless
Posts: 1
Registered: 10-2-2016
Member Is Offline
Mood: No Mood
|
|
Ph tester for solids
Hello everyone,
First of all thank you for your help.
I'd like to know if there are any ph testers for solids not diluted, where can I buy them and how much would they cost.
Thanks
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
A solid which is not diluted does not have a pH. There is a thread on understanding Bronsted-Lowry acid-base theory that you should read. You can find
it using the search engine.
|
|
|
Detonationology
Hazard to Others
Posts: 362
Registered: 5-5-2015
Location: Deep South
Member Is Offline
Mood: Electrophillic
|
|
pH is calculated and measured by the quantity of H+ ions in solution. To my knowledge, ions will not dissociate when solid, but don't
quote me.
Hmmm. Now I'm curious what were to happen to the ions in anhydrous sulfuric acid if were to somehow become frozen? They wouldn't be able to freely
dissociate, right?
“There are no differences but differences of degree between different degrees of difference and no difference.” ― William James
|
|
|
phlogiston
International Hazard
Posts: 1379
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline
Mood: pyrophoric
|
|
It will definately help if you could explain what you are trying to accomplish.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
|
|
DraconicAcid
International Hazard
Posts: 4356
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
pH is only meaningful in dilute aqueous solution.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by JJay  | | A solid which is not diluted does not have a pH. There is a thread on understanding Bronsted-Lowry acid-base theory that you should read. You can find
it using the search engine. |
Here it is:
http://www.sciencemadness.org/talk/viewthread.php?tid=65082
| Quote: Originally posted by Detonationology | pH is calculated and measured by the quantity of H+ ions in solution. To my knowledge, ions will not dissociate when solid, but don't
quote me.
Hmmm. Now I'm curious what were to happen to the ions in anhydrous sulfuric acid if were to somehow become frozen? They wouldn't be able to freely
dissociate, right? |
The first point is really incorrect or at least very old fashioned: aqueous solution contain no free protons (H<sup>+</sup> , only oxonium ions: H3O<sup>+</sup> (also some
H5O2<sup>+</sup> and higher).
Your second point: H2SO4 can vis-a-vis an even stronger acid behave like a base and be protonated to
H3SO4<sup>+</sup>.
The equilibrium in totally anhydrous H2SO4:
2 H2SO4 < === > H3SO4<sup>+</sup> + HSO4<sup>-</sup>
... is likely to be very left-leaning though.
[Edited on 10-2-2016 by blogfast25]
|
|
|
Detonationology
Hazard to Others
Posts: 362
Registered: 5-5-2015
Location: Deep South
Member Is Offline
Mood: Electrophillic
|
|
I suppose I'll have a look at the Bronsted-Lowry thread as well to have a more lucid understanding. Thank you for your contributions.
“There are no differences but differences of degree between different degrees of difference and no difference.” ― William James
|
|
|
DraconicAcid
International Hazard
Posts: 4356
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
| Quote: Originally posted by blogfast25 |
The equilibrium in totally anhydrous H2SO4:
2 H2SO4 < === > H3SO4<sup>+</sup> + HSO4<sup>-</sup>
... is likely to be very left-leaning though.
|
The autoionization of sulphuric acid is actually much more facile than that of most solvents. I seem to recall reading in Cotton and Wilkinson that
it's about 10<sup>-4</sup>.
[Edited on 10-2-2016 by DraconicAcid]
[Edited on 10-2-2016 by DraconicAcid]
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by DraconicAcid |
The autoionization of sulphuric acid is actually much more facile than that of most solvents. I seem to recall reading in Cotton and Wilkinson that
it's about 10-4. |
Did you mean 10<sup>-4</sup>?
[Edited on 10-2-2016 by blogfast25]
|
|
|
DraconicAcid
International Hazard
Posts: 4356
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
Yes, and I thought I put in the script for that.....
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
