I did an experiment where I set up a galvanic cell. It consisted of two half cells, one with a (zinc) galvanised iron strip and iron nitrate and the other with a copper strip and copper nitrate. There was a potassium hydroxide salt bridge and the two electrodes where connected with a wire lead. After a day, I found that the galvanised iron strip had a layer of black all over it. I was just wondering what this black deposit could be and by what reaction was it formed? Initially I thought it was iron oxide however this is not black. I now think it might be something related to zinc.
Please reply soon!!! thanks