Homework Help: Qsp Calculations

1. Feb 15, 2006

pmahesh107

Calculate the ion product to determine if a precipitate will form when 125 mL .00500 M sodium chloride is mixed with 125 mL .00100 M silver nitrate solution.

NaCl + AgNO3 -> NaNO3 + AgCl

Net ionic equation = 2AgCl -> 2Ag + Cl2

[Ag+] before = .00100 after = .00050
[Cl-] before = .00500 after = .00250

My question was about the Qsp. Would the Qsp = (.00050)(.00250) or Qsp = (.00050)^2(.00250) I don't understand which co-efficients to look at, the one in the equation or the one in the net-ionic equation. Thanks in advance for the help.

2. Feb 16, 2006

Haxx0rm4ster

Your question is very confusing.
The 1st and 2nd equation are different...as well flipped in a way...

you are saying one of the products is Chlorine gas... and the reactant is AgCl, which is a product of the first equation.
the netionic eq qould be Cl(-) + Ag(+) --> AgCl, and i dont know why you are trying to balance it out.
Remember its a solution, so you can have Cl(-) ions by themselves.

Are you trying to find the reaction quotient??

3. Feb 16, 2006

Staff: Mentor

It is not a correct net ionic equation for this reaction. If you mix soluble silver salt with chlorides, silver chloride precipitates.

4. Feb 17, 2006

pmahesh107

why is it Cl(-) + Ag(+) --> AgCl ? don't you have to balance it out? i asked my teacher and she said to use the co-efficient from the net ionic equation

5. Feb 18, 2006

Staff: Mentor

And Cl- + Ag+ --> AgCl is the balanced net ionic equation of AgCl precipitation.