[adrian]

You observed in the equation that you have mole/mole stoechiometry. Then your real problem is how many moles of AgNO3 you have in the solution.
The answer is: 2500 mL=2.5Lx0.0113=.. calculate yourself.
The result is exact No of NaCl moles you must use.
The last step is calculating the quantity of NaCl/ grams.
Concerning the "loss of NO3 ions": pls do not complicate the problem, is irrelevant.