Sciencemadness Discussion Board

Cleaning silver electrodes

mycotheologist - 6-5-2012 at 07:45

I notice that silver electrodes eventually turn black. The black stuff must be silver oxide (AgO2). Silver oxide is a mild oxidising agent so I tried soaking the electrodes in a solution of sodium metabisulfite (a reducing agent) but no reaction occurs. Would I have better luck by soaking them in an acid?

hissingnoise - 6-5-2012 at 07:47

Most probably! Dilute HNO<sub>3</sub>, most likely . . .

barley81 - 6-5-2012 at 10:34

Clean them like you clean tarnished silver in the kitchen: dissolve some baking soda in water, put an aluminum foil sheet in the solution, and then drop in the silver. The aluminum reduces the silver compounds that are adhering to the silver.

@hissingnoise when did you stop being Pulverulescent?

[Edited on 6-5-2012 by barley81]

phlogiston - 6-5-2012 at 13:45

The black layer is usually silver sulfide actually. Silver does not tarnish in oxygen.