How much energy in kJ is released when 15.72 g of aluminum react with an excess of copper oxide? 3 CuO + 2 Al -> 3 Cu + Al2O3 AH = 1190 kJ/mol

Silver tarnishes as silver metal reacts with hydrogen sulfide, h2s, in the air. in this reaction, dark silver sulfide, au2s, covers the surface of silver. when silver is polished, this coating of silver sulfide can be removed from the surface. this makes the silver shiny again. enter the coefficients that balance the tarnishing reaction equation. (type 1 for no coefficient.)