Question

how many grams of each species will be present at the end when 0.500g of copper is added to 2.500g of AgNO3?

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

Answer 1

Here is a worked example of a stoichiometry problem.
http://www.jiskha.com/science/chemistry/stoichiometry.html