Silver nitrite, AgNO2 (47.8 mg), was dissolved in water to make 10.00 mL of solution. Then 3.00 mL of that solution was used to make a new solution with a total volume of 1.000 L. What was the concentration of the silver ion in the final solution?

Answer 1

Silver nitrate is AgNO3. You made a typo.

47.8 mg = 0.0478 g = ? mols.
mols = 0.0478/molar mass AgNO3 = approximately 0.00028 in 10 mL = 0.00028/0.01 = about 0.028M
Then 0.028 x (3.00/1000) = ? M.