518 SMITH'S INTERMEDIATE CHEMISTRY 



the electrolytic refining of copper, does this phenomenon illus- 

 trate? 



3. How could you .recognize cupric sulphate solution by show- 

 ing that it contained, (a) cupric-ion, (b) sulphate-ion (p. 270)? 



4. Make an equation for the liberation of mercury from cinna- 

 bar. 



5. What gases should you collect over mercury? 



6. What other Halts, beside those of mercury, are volatile? 



7. Ho 7 should you recognize a salt of mercury in solution? 



