Why does Cu 2 AgNO3 Cu NO3 2 2 Ag occur but the reverse reaction does not?

Answer 1

Cu2+ + 2AgNO3 --------> Cu(NO3)2 + 2 Ag+, due to high charge density for Copper ion as compare to Silver ion the reverse is not possible in aqueous solution.

Answer 2

The forward reaction Cu + 2 AgNO3 -> Cu(NO3)2 + 2 Ag occurs because copper is more reactive than silver, displacing it from the silver nitrate solution. The reverse reaction does not occur because silver is less reactive than copper and is unable to displace copper from its nitrate solution. This is due to the reactivity series of metals and their ability to displace one another in a chemical reaction.