Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Solubility with multiple compounds - how do they effect each other?
RogueRose
International Hazard
*****




Posts: 1594
Registered: 16-6-2014
Member Is Offline


[*] posted on 4-12-2016 at 17:53
Solubility with multiple compounds - how do they effect each other?


I'm curious how adding multiple compounds such as NaCl and KNO3 into water would effect the amount of each compound that can be dissolved at any given temp. Lets say that NaCl can dissolve at 300g/L and KNO3 at 800g/L at the same temp (20-25C) - when each is dissolved individually. If both are dissolved into the same liter of water, will it dissolve 300g & 800g of the salt and nitrate respectively or will it be greatly reduced like 150g and 400g or 200g & 600g?

I'm interested in other compounds like CuSO4, Ca(NO3) and KCl (really take your pick of salts....) mixed together and finding out how they effect total solubility of each compound when compared to other compounds in the mix. So more than 2 compounds I'm also wondering about.

View user's profile View All Posts By User
HeYBrO
Hazard to Others
***




Posts: 289
Registered: 6-12-2013
Location: 'straya
Member Is Offline

Mood: :)

[*] posted on 4-12-2016 at 18:42


here read these:
http://chem.libretexts.org/Core/Physical_and_Theoretical_Che...
http://chem.libretexts.org/Core/Physical_and_Theoretical_Che...
View user's profile View All Posts By User
Metacelsus
International Hazard
*****




Posts: 2539
Registered: 26-12-2012
Location: Boston, MA
Member Is Offline

Mood: Double, double, toil and trouble

[*] posted on 5-12-2016 at 05:43


You should read up on activity coefficients and ionic strength. In many cases, a high concentration of one salt will allow more, not less, of an unrelated salt to dissolve.



As below, so above.

My blog: https://denovo.substack.com
View user's profile View All Posts By User
RogueRose
International Hazard
*****




Posts: 1594
Registered: 16-6-2014
Member Is Offline


[*] posted on 5-12-2016 at 06:17


Quote: Originally posted by Metacelsus  
You should read up on activity coefficients and ionic strength. In many cases, a high concentration of one salt will allow more, not less, of an unrelated salt to dissolve.


Wow! That is totally unexpected! I'll look into this. That make some things very interesting!!
View user's profile View All Posts By User
yobbo II
National Hazard
****




Posts: 764
Registered: 28-3-2016
Member Is Offline

Mood: No Mood

[*] posted on 5-12-2016 at 07:49


Quote: Originally posted by Metacelsus  
You should read up on activity coefficients and ionic strength. In many cases, a high concentration of one salt will allow more, not less, of an unrelated salt to dissolve.


Surly that cannot be right?

Start here for just two compounds.

https://www.sciencemadness.org/whisper/files.php?pid=252390&...
View user's profile View All Posts By User
solo
International Hazard
*****




Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline

Mood: ....getting old and drowning in a sea of knowledge

[*] posted on 5-12-2016 at 08:06


...maybe a pictorial might help.....solo

https://www.khanacademy.org/science/chemistry/acid-base-equi...




It's better to die on your feet, than live on your knees....Emiliano Zapata.
View user's profile View All Posts By User
Metacelsus
International Hazard
*****




Posts: 2539
Registered: 26-12-2012
Location: Boston, MA
Member Is Offline

Mood: Double, double, toil and trouble

[*] posted on 5-12-2016 at 08:57


Quote: Originally posted by yobbo II  
Quote: Originally posted by Metacelsus  
You should read up on activity coefficients and ionic strength. In many cases, a high concentration of one salt will allow more, not less, of an unrelated salt to dissolve.


Surely that cannot be right?


Quote:

In general, the addition of an “inert” salt (KNO3) to a sparingly soluble salt (CaSO4) increases the solubility of the sparingly soluble salt.

http://chem320.cs.uwindsor.ca/Notes_files/320_l07.pdf

Yes, this is counterintuitive. Conceptually, the potassium and nitrate ions "shield" the calcium and sulfate ions from each other.

[Edited on 12-5-2016 by Metacelsus]




As below, so above.

My blog: https://denovo.substack.com
View user's profile View All Posts By User
DraconicAcid
International Hazard
*****




Posts: 4334
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline

Mood: Semi-victorious.

[*] posted on 5-12-2016 at 09:06


Quote: Originally posted by yobbo II  
Quote: Originally posted by Metacelsus  
You should read up on activity coefficients and ionic strength. In many cases, a high concentration of one salt will allow more, not less, of an unrelated salt to dissolve.


Surly that cannot be right?


Sure it is. If you have a high ionic strength, the solution ceases to be pure water (or "just like pure water"), and becomes more similar to an ionic liquid. Ergo, ionic compounds become more soluble in it. There are some hydrated ionic salts that can be used as low-temperature melts (calcium nitrate tetrahydrate, I recall, is one of them); you could view it as a molten salt containing some water, or a really really concentrated calcium nitrate 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.
View user's profile View All Posts By User

  Go To Top