Potassium Nitrate in Water: What Happens?

[Kyoma]

If you add potassium ions into a solution of nitrate ions and water, what will happen? Will the final mixture contain potassium nitrate and water or a mixture of potassium, nitrate ions and water molecules? :l

 

[Nemus]

Just solvated ions in a dilute solution. If you make a very concentrad solution they begin to pair up and finally to form crystals.

 

[epenguin]

There can't be just nitrate ions and water, there have to be some counter ions, Na⁺ or H⁺. Likewise you can't add just potassium ions.

 

[Nemus]

Well, I could start with a dilute solution of nitric acid and add KOH and I'd end up with K+ and NO3- and water. Only.

 

[Borek]

Well, I could start with a dilute solution of nitric acid and add KOH and I'd end up with K+ and NO3- and water. Only.

How is it related to the original question and epenguin comment? Every solution you mention contains ion and counterion, while the OP asked about solution containing ONLY an ion.

 

[epenguin]

Well, I could start with a dilute solution of nitric acid and add KOH and I'd end up with K+ and NO3- and water. Only.

You would end up with K⁺ but then you are starting off with K⁺ in the solution you add. You have transferred that many K⁺ from a bottle to a beaker maybe. Likewise you end up with NO₃^- and they are the same ones you started off with. The only happening thing when you do this mixture is that the OH^- react with the H⁺ to form H₂O. If you add more of the OH^- (which = the K⁺ in the KOH) than there are of H⁺ (which = the NO₃^- in the nitric acid) the solution will be alkaline, if you add less it will be acid, there are a thousand calculations on this site about that and variations of it in which students sometimes find some difficulty due to various avoidable confusions. The reaction just mentioned generates some heat which if the solutions are dilute will not be dramatic but might be measurable with a thermometer, I don't know figures offhand.

You took me back to about my first chemistry lesson when after various reactions were finished we asked 'Sir, what happens if you mix that and that?'. 'Nothing' he replied, and then sensing our disappointment added 'It won't explode or anything.'