posted by Jill on .
How many moles of sodium chloride must be added to an aqueous solution that contains 2.0 moles of silver nitrate
in order to precipitate 0.50 moles of silver chloride?
A) 0.25 mol
B) 0.50 mol
C) 1.0 mol
D) 2.0 mol
E) 1.5 mol
The answer is B. I have no idea what to do. I was just messing around and did some dimensional analysis, but I don't think this will help me get the right answer.
I did this:
(2.0mol AgNO3) (1 mol AgCl/4 mol AgNO3), which gives me the .50 mol AgCl. What am I missing?
Thanks a lot!
You have to look up the solubility of silver nitrate in water. Look that up. Now calculate what the beginning concentration, subtract that from the allowed solubility, and you have the concentration to be added, and given volume, you know the amount you can add.
I'm sorry. I'm still not sure I understand. I know that all compounds with Nitrate are soluble, but I don't get what I need to do.