Red-Ox Reactions and their Stoichiometry

Question

If 2.34 g of copper are added to a solution of silver nitrate a concentration such that this last reactant is in excess; 7.95 g of metallic silver are formed. which would be the stoichiometry ratio between silver nitrate and copper?

Answer 1

2.34 g Cu x 1 mol Cu / 63.6 g = 0.0368 mols Cu

7.95 g Ag x 1 mol Ag / 108 g = 0.0736 mols Ag

Thus, the mol ratio of Ag : Cu is 2 : 1

So, we can write the following balanced equation:

Cu(s) + 2AgNO₃(aq) ==> 2Ag(s) + Cu(NO₃)₂(aq)

The stoichiometry ratio between silver nitrate and copper would be 2 : 1