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Determinig the ion concentration in solution

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angelguy:
Hi all,

System :
I have a solution of different salts such as CaCl2,MgSO4,NH3H2PO4,KCl, NaCL,Glycerol and so on. As we all know this salts will dissociate in their corresponding ions.
Also I have to add CO2 in the solution(but not sure about it). And can maintain its pH by adding acid or base.

Question:

I need to determine the concentration of all this ions formed. Since I have no idea about anaytical chemistry, sorry to ask you this silly question.

Angelguy

angelguy:
I really dunt have any idea about analytical chemistry so please make me understand in simple terms.I will be very thankful to each reply and comments on this.


angelguy

arnyk:
Are you adding all those into a single solution?  It doesn't matter anyways I don't think...all you need to know are the amount (moles) of each salt you have in solution.  Then figure the moles of the specific ion in each salt (for every 1 mole of the salt, how many moles of the ion will there be?).  For [] you would also need the total volume of the solution.

For example: I have 3 mol of KBr, and 5 mol of K3PO4 in a 10L solution.  What is the [K+] in solution.

For every 1 mol of KBr, I also have 1 mol of K+ ions.  Therefore, there will be 3 mol of K+ in 3 mol of KBr.

For every 1 mol of K3PO4, I have 3 mol of K+ ions.  Therefore, there will be 15 mol of K+ in 5 mol of K3PO4.

Add the moles together of the K+ ions: 3 + 15 = 18 mol of K+ ions in solution.

[K+] = n/V
        = (18)/(10)
        = 1.8 M

Now do that, except with all of those salts you have there.

angelguy:
hey.. thanks for your reply however, I am done with that stiochionetry thingy.

My object is , I have the known pH of the solution and therefore i have known H+ content and will maintain the same content, evenif there is changes in the H ion concentration, by adding acid or base.
Therefore< i have determined the concentration of all the ions theretically. I need to verify my results by doing actualy experiment. I hope you will understand what i mean.

I have taken certain steps in doing the stuff. Please let me know if i am in right direction.

1). How about adding the EDTA and titrate it ?
2). Or forming MgOH2 precipitate( but i think this will not be in significant amount to hold in the filter paper) :) Please let me know the expert advice in this.

Thanking you once again and hoping for similiar response.


Angelguy

asqa:
if you titrate against EDTA you will get total hardness(Ca+Mg) but if you make the solution as hydroxide Mg forms Mf(OH)2 it will not give response to EDTA if you use calcon indicator.
but in your question you want to know the conc. of ions. so what should you do is, you find the anion and cation conc sepaerately and convert it to corresponding salt.

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