A coin made of silver with a mass of 5.82 grams is dissolved by reacting with HNO3. When we add NaCl to the solution, a silver salt precipitates and has a mass of 7.20 grams. Determine the percentage of silver in the coin.
The answer is supposed to be 93,1% ...But I don't really know how to solve this problem, for now I figured that the reaction's equation is:
2Ag(s) + 2HNO3(l)+2NaCl(s)→ 2AgCl(s) + 2NaNO3(l) +H2(g)...but I might be wrong!