Sciencemadness Discussion Board

Reactions between soluble salts?

bolbol - 30-6-2016 at 13:16

We have two 500 mL solutions, A and B.
Solution A = 1.0 M KNO3
Solution B = 1.0 M NaBr

If we mix the solutions no reaction is supposed to occur since a gas or an insoluble salt wont be formed.
If solutions A and B are mixed then there will be ions of K+, Na+, Br-, and NO3- in solution.

So my question is, if the water in solution is boiled off, will the salt precipitate be a mixture of KNO3 and NaBr or will I also have some sodium nitrate and potassium bromide as well?

ficolas - 30-6-2016 at 13:30

The salt with the less solubility will precipitate first, then a mix between the salt with the less solubility and the 2nd salt with the less solubility will precipitate and so on.
I tried my best, but a better explanation can be found here https://m.reddit.com/r/chemistry/comments/37ktnx/solution_of...

[Edited on 30-6-2016 by ficolas]

bolbol - 30-6-2016 at 13:34

Makes sense, thank you!

If I were to do such an experiment, are there any analytical methods that would tell me how much of each salt I have in the final precipitate?

ficolas - 30-6-2016 at 15:18

Yes, it is possible knowing the solubilities.
This is what I came up with. Supossing 1 mol lf AC, and 1 mol of BD, in 1L of water, with the listed solubilities, I calculated the amount of AC that precipitates, then it would get a bit more complex foe the pecipitation of the mixture of AC and AD, and lastly, everything would precipitate as a mixture of AC, AD, BD and BC would never precipitate.

NOTE: I am probably wrong, and I maybe shouldnt be posting this message, but I think it could help me if somebody corrects me, or who knows, maybe I am not wrong. So bolbol, better wait for somebody with more knowledge to answer :P

Image: (Sorry foe using a notebook and for the image size, just ignore this if it bothers you :s)
http://i.imgur.com/k9M8hWf.jpg

[Edited on 30-6-2016 by ficolas]

[Edited on 30-6-2016 by ficolas]

bolbol - 30-6-2016 at 17:26

I meant to ask if they are any instruments that could detect such a thing.