(2) The solution turns blue, indicating that the solution contains copper ions, further indicating that the patina contains copper.
2.( 1) The patina will decompose into three oxides when heated. The chemical equation for the decomposition of copper rust is: Cu 2 (OH) 2 CO 3? △? . ? 2CuO+H 2 O+CO 2 ↑。
(2) According to the composition of the patina and the data consulted, the patina may be formed by the interaction of copper with oxygen, water and carbon dioxide.
(3) After a long period of experiments, it is found that the copper in the D tube rusts the most, because the copper in the D tube is in full contact with oxygen, water and carbon dioxide, and it is easy to rust.
(4) An experiment that needs to be supplemented is to put the copper sheet into a test tube filled with dry air (or oxygen and carbon dioxide) for comparative observation.
(5) Xiaoming's analysis is not comprehensive; Because the two bronzes were collected from different places, the conditions are different and cannot be compared.