Copper is placed above the silver in the reactivity series which indicates that copper is more reactive than silver. When a copper coin or strip is kept immersed in a solution of silver nitrate (AgNO3), silver from its solution will deposit on copper coin.
2AgNO3(aq) + Cu(s) -------> 2Ag(s) + Cu(NO3)2 (aq)
Colourless Blue
Copper slowly displaces silver from the AgNO3 solution and the colour of solution changes from colourless to blue due to the formation of copper nitrate [Cu(NO)2]. The copper coin will disappear and silver will precipitate out.
