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May 5, 2016

# Homework Help: Chemistry

Posted by Ryan on Friday, March 16, 2012 at 6:48pm.

An aqueous solution that 2.10 M in AgNO3 is slowly added from a buret to an aqueous solution that is 1.20×10^−2 M in Cl- and 0.260 M in I- .

When the second ion begins to precipitate, what is the remaining concentration of the first ion?
• Chemistry - DrBob222, Friday, March 16, 2012 at 8:32pm

You should have typed in the Ksp for AgCl and AgI. The Ksp I look up probably aren't the same as in your text. I will use approximations.
Ksp for AgI = about 10^-17.
Ksp for AgCl = about 10^-10
Therefore, AgI will ppt first. AgCl will ppt second.
What will be the (Ag^+) when AgCl just starts to ppt.
That will be (Ag^+) = Ksp/(Cl^-) = 10^-10/0.012 = ?
Now what will be the (I^-) at this point? That will be (I^-) = Ksp/(Ag^+) just calculated.
Post your work if you still need help.

• Chemistry - Ryan, Friday, March 16, 2012 at 8:57pm

I got it thanks

• Chemistry - anon, Friday, June 8, 2012 at 1:38am

But how did you get the (Cl^-)?

• Chemistry - A, Tuesday, October 29, 2013 at 11:04am

HELP