The balanced chemical reaction is written as:
Zn + 2AgNO3 = Zn(NO3)2 + 2Ag
To determine the grams of silver metal that is being produced, it is important to first determine which is the limiting reactant and the excess reactant from the given initial amounts. We do as follows:
4.35 g Zn ( 1 mol / 65.38 g ) ( 2 mol AgNO3 / 1 mol Zn ) = 0.1331 mol AgNO3 needed
35.8 g AgNO3 ( 1 mol / 169.87 g ) ( 1 mol Zn / 2 mol AgNO3 ) = 0.1054 mol Zn needed
Therefore, the limiting reactant would be the zinc metal since it would be consumed completely in the reaction. The excess amount of AgNO3 would be:
0.2107 mol AgNO3 - 0.1331 mol AgNO3 = 0.0776 mol AgNO3 left ( 169.87 g / 1 mol ) = 13.19 g AgNO3 left
0.0665 mol Zn ( 2 mol Ag / 1 mol Zn) ( 107.9 g / 1 mol) = 14.3581 g Ag produced
