In an electrolytic refining process, the anode is made of impure metal, and the cathode is made of a strip of pure metal. When an electric current is passed through the electrolyte, metal ions from the electrolyte are deposited as a pure metal on the cathode. A soluble silver salt is used as an electrolyte in the electrolysis of silver metal because it allows for the deposition of a pure metal on the cathode.

In the electrolysis of silver metal, you cannot use any rod at the anode; it is crucial to use a silver rod as the anode because the process relies on the oxidation of silver ions from the silver anode into the solution to deposit pure silver at the cathode; using a different metal would not produce the desired result. The net result is that silver metal has been transferred from the anode to the cathode.

In summary, a silver rod is used at the anode, the spoon has to be cathode since we must obtain a pure silver spoon while the electrolyte must be a soluble silver salt because it allows easy deposition of metal ions as a pure metal on the cathode.