Why does adding #"AgNO"_(3("aq"))# to #"I"_(2("s")) rightleftharpoons "I"_(2("aq"))# cause the aqueous iodine to precipitate into a solid?
Here's what I think.
There are two more equilibria involved:
Here's my take on this:
Iodine reacts with water and the following equilibrium is established:
The position of equilibrium lies well to the left.
Adding aqueous silver nitrate would cause a yellow precipitate of silver iodide to form:
On this basis, according to Le Chatelier, you would expect the position of equilibrium to be shifted to the right, causing more solid iodine to dissolve.
The question states that the opposite takes place.
I think this hinges on how you interpret exactly what you mean by
In reality, because of the low solubility of iodine in water, it is actually a solution of iodine in potassium iodide solution.
The equilibrium is established:
If the question actually means that