When treated with nonoxidizing acids (HCl, CH 3 COOH) sulfides react to liberate H 2 S gas (rotten-egg odor). If the sulfide is very insoluble liberation of the gas may require concentrated acids (indeed some sulfides, HgS, CuS, are so insoluble that dissolution requires special treatment). The gas is generally identified by its odor and its precipitation of colored sulfides of various metal ions. Sulfides or hydrogen sulfide also are oxidized to elemental sulfur and sulfate by oxidizing agents such as permanganate, nitric acid, sulfuric acid, Fe(III), etc.
QDA software serves to provide insights into qualitative data sets without suggesting interpretations. Based on a content analysis, the researcher can draw conclusions about the respective object of research (. interview data). Software tools for qualitative data and text analysis allow for easy sorting, structuring, and analyzing of large amounts of text or other data and facilitate the management of the resulting interpretations and evaluations. MAXQDA is one of the pioneer software programs in this field: the first version of MAXQDA was released as early as 1989!