[edwinj]

I have some basic doubts.

When we dissolve some salts in water, are they separating as ions and do they exist as independent ions?

In the case of CuCl2 dissolved in water is it forming Cu(2+) and 2Cl(1-)?
If so, will that Cl(1-) react with hydrogen in water to form HCl?(Because, before adding CuCl2 water is showing pH~7 and after adding 0.1M of CuCl2 it turned to pH~4.5)
Can we use this change in pH as a comparative measure to calculate number of Cu(2+) ions in the solution?

My aim is thin film preparation using adsorption principle. For this I will dip a glass substrate in the CuCl2 solution. The Cu(2+) ions will get adsorbed in it. I think the independent Cu(2+) ions are getting adsorbed.
In order to get maximum independent Cu(2+) what all parameters should i change? Like adding some acids/bases/or other chemical to separate out Cu(2+) and get them adsorbed.


I am with a physics background.
Many of my understandings and assumptions in the above may be wrong.
Like to get them corrected.
Also it will be great help if you can explain some basics.

[Arkcon]

I have some basic doubts.

That's OK, we're here to help, but so many things that you say are simply incorrect, that its hard to make a coherent idea of the things you say.  I'm going to try to take this point by point, but you ask so many things ... well, let's try anyway.

When we dissolve some salts in water, are they separating as ions and do they exist as independent ions?

This is a generally accepted model we use for visualizing the concept yes.  Not absolutely true, but we work with what we can.

In the case of CuCl2 dissolved in water is it forming Cu(2+) and 2Cl(1-)?

We can work with that yes.  We also generally try to envision solvated ions as surrounded by water molecules, although that is also simply a model, and not absolutely true.

If so, will that Cl(1-) react with hydrogen in water to form HCl?

No, that's not what happens.  Can you see why?  If you have CuCl₂, and you dissolve it in water, and then evaporate the water, don't you get the solid CuCl₂ back?   If what you described happened, would we lose some when we dried it?  If you made HCl by this process, what would happen to the "O" in water, or the copper left behind?  You neglected that.

(Because, before adding CuCl2 water is showing pH~7 and after adding 0.1M of CuCl2 it turned to pH~4.5)

The pH change is caused by Cu²⁺ in water.  Salts of transition metals are slightly acidic in water solution, by their interaction with their solvating water molecules.

Can we use this change in pH as a comparative measure to calculate number of Cu(2+) ions in the solution?

Interesting, you seemed to know that transition metal ions are acidic, and seemed to not know it before .  I don't know if you can get great resolution of transition metal ion concentration and pH dependance, but you can always try and see.

My aim is thin film preparation using adsorption principle. For this I will dip a glass substrate in the CuCl2 solution. The Cu(2+) ions will get adsorbed in it. I think the independent Cu(2+) ions are getting adsorbed.
In order to get maximum independent Cu(2+) what all parameters should i change? Like adding some acids/bases/or other chemical to separate out Cu(2+) and get them adsorbed.

I have no idea at all if this materials chemistry plan of yours will work at all.  If you have a peer-reviewed reference, I'd like to read it.

I am with a physics background.
Many of my understandings and assumptions in the above may be wrong.
Like to get them corrected.
Also it will be great help if you can explain some basics.

Glad to help.  Please remember you wrote this bit when you review my comments.

[edwinj]

Here is one journal paper.

I think you can get some idea from it.

[edwinj]

Thank you Arkcon

[Arkcon]

Thank you for the reference, I had no idea it was that easy.  When I get a chance, I should read the references to try to understand how durable and useful such precipitated thin films are.