CALCULATION OF CONDITIONAL EQUILIBRIUM IN SERIAL MULTIPLE PRECIPITATION OF METAL SULFIDES WITH HYDROGEN SULFIDE STREAM GENERATED FROM SODIUM SULFIDE: A DIDACTIC TOOL FOR CHEMISTRY TEACHING

Renata Bellová, Danica Melicherčíková, Peter Tomčík
2016 Química Nova  
Hydrogen sulfide is presented in textbooks as toxic, environmentally unacceptable species, however some positive effects in human metabolism were discovered in the last decades. It is important to offer students also some new information about this compound. As didactic tool in this case may serve serial precipitation of Cd 2+ , Cu 2+ , Zn 2+ , Mn 2+ and Pb 2+ ions forming various colored sulfides in bubblers with chemically generated hydrogen sulfide stream. This experiment has strong and
more » ... se color effect for enhancing the visual perception to motivate students to understand more abstract and complex information about hydrogen sulfide. It also may be helpful in analytical chemistry courses for conditional precipitation equilibrium teaching and calculations.
doi:10.5935/0100-4042.20160062 fatcat:aoklyy4tijbope5zindbivauuy