A strip of copper is placed in four different colourless salt solutions. Which one of the solutions will finally turn blue?
A typical reaction with silver nitrate is to suspend a rod of copper in a solution of silver nitrate and leave it for a few hours. The silver nitrate reacts with copper to form hairlike crystals of silver metal and a blue solution of copper nitrate.
2AgNO3+Cu→Cu(NO3)2+2Ag