I found a bunch of decorative pieces in my garage that I want to scrapThey are all round and have a dark yellowish/greenish color to themI used one against my grinder and after scraping it it leaves a white space on itI know brass should be yellow like after scraping it but these pieces seem to weigh too much to be aluminumIs there any way to tell the difference?
Buy a bottle of TarnX at Walmart or the local grocery storeTarnX makes brass real shiny, but it does nothing to aluminum, That's a quick way to tell the differenceSince both metals are non-magnetic you cannot use a magnet to tell the difference like you could in telling the difference between steel and aluminum.
Atomic weights: Al27 O16 Al2O3102 If the yield is 89.3% 0.893, then the amount of Al2O3 needed is 1/0.893 1.12 112% of the theoretical amount needed385gAl x 1molAl/27gAl x 2molAl2O3/4molAl x 102gAl2O3/1molAl2O3 x 1.12 814g Al2O3
