Copper Sulfate 61 



NOTES 



Bluestone or copper sulfate is the impor- 

 tant salt of copper for agriculture. Its weak 

 solution is fungicide and a disinfectant. 

 Seed wheat is treated with it to kill the 

 spores of the smut. Bordeaux mixture and 

 Paris green are made from it. 



Copper does not dissolv in acids without 

 first being oxidized. This may be accom- 

 pHsht, superficially, by heating in air when 

 the resulting coating of black copper oxid 

 will dissolv in sulfuric acid. Copper may be 

 fused with sulfur when the resulting copper 

 sulfid will respond to the action of sulfuric 

 acid. The unreduced copper sulfid of copper 

 matte which falls to the bottom of the tank 

 when crude copper is electrolytically purified 

 is used to make copper sulfate. Copper 

 moistend with acid will take oxygen from the 

 air and dissolv slowly. In this experiment 

 the oxygen is obtaind from nitric acid. 



QUESTIONS 

 (To be answerd in the notebook.) 



1. From the sjTnbol, CUSO4 • 5H2O, calculate the 

 amount of crystallized salt that may be made from 10 

 grams of metaUic copper. 



2. From the same symbol find out how many grams 

 of suKuric acid would be necessary. 



3. Consult the table of the density of sulfuric acid 

 under superphosphate and determin how many cubic 



