Hi I have a problem with this:
Electrolyzing a solution of a ruthenium sale for 500 seconds with a current of 120 mA deposited 31.0 g of metallic ruthenium. How much is the
oxidation number of ruthenium in the salt used?
i=Q/t => Q=0.12*500= 60 C
m=Q/F * PM/z => z=Q*PM / F*m = 0.002
The result is impossible...