Gooch and Edgar — Reduction of Vanadic Acid. 235 



fitted with a separatory funnel through which dilute sulphuric 

 acid was added from time to time in small portions as required 

 during the prolonged action, never evolving hydrogen violently 

 enough to float the magnesium. 



The experiments of Table I, C, were made to test the effect 

 of using magnesium in the form of a heavy amalgam. About 

 two grams of magnesium were dissolved, with heating, in an 

 excess of mercury and the resulting liquid amalgam was used 

 as the reducing agent, in the flask containing vanadic acid and 

 sulphuric acid. At the end of the action, which took place 

 without the application of heat and was over in about ten 

 minutes, the distinctly violet solution was decanted, filtered 

 from the mercury with careful washing, and titrated with 

 potassium permanganate. Special tests in blank having shown 

 that, for the amount of amalgam used, mercury goes into solu- 



Time 



Magne 

 sium 

 met. 



grm. 



KMn0 4 



N 



10 



Table I. 



V 2 5 V 2 5 



taken as calc. from 



Error 



in terms 



of V 2 5 



052 



NaV0 3 oxidation 



of V 2 O s 



grm. 



A 

 Eedueed by Magnesium and Hydrochloric Acid 



V 2 2 

 reduced to 



cm- 1 



V 2 3 

 grm. 



C 

 Eedueed by Magnesium- Amalgam and Sulphuric Acid 

 Calculated 

 from V 2 2 



V 2 2 

 grm. 



1 hr. 



4-0 



26-05 



0-1144 



0-1249 



+ 0-0105 



0-0934 



0-0210 



1 hr. 



4-0 



26-2 



0-1144 



0-1257 



+ 0-0113 



0-0918 



0-0226 



1* hr. 



4-0 



27-1 



0-1144 



01300 



+ 00156 



0-0834 



0-0312 



l£hr. 



4-0 



28-3 



0-1144 



0-1357 



+ 0-0213 



0-0718 



0-0426 







Reduced by Magne 



B 



sium and 



Sulphuric Acid 





8 hrs. 



4-0 



24-1 



0-1144 



0-1156 



+ 0-0012 



0-1120 



0-0024 



8 " 



4-0 



23-8 



0-1144 



0-1142 



— 0-0002 











8 " 



4-0 



25 '2 



0-1144 



0-1208 



+ 0-0064 



0-1015 



0-0129 



8 " 



4-0 



25-4 



0-1144 



0-1218 



+ 0-0074 



0-0996 



0-0148 



16 " 



8-0 



26-5 



0-1144 



0-1271 



+ 0-0127 



0-0890 



0-0254 



16 " 



8-0 



26-1 



0-1144 



0-1252 



+ 0-0108 



0-0928 



0-0216 



20 " 



12-0 



26 8 



0-1144 



0-1285 



+ 0-0141 



0-0861 



0-0283 



10 min. 



2-0 



32-1 



0-1144 



0-1027 



— 0-0117 



0-0353 



0-0791 



10 " 



2-0 



33-4 



0-1144 



0-1068 



— 0-0076 



0-0228 



0-0916 



10 " 



2 



34-1 



0-1144 



0-1090 



— 0-0054 



0-0161 



0-0983 



10 " 



2-0 



32-4 



0-1144 



0-1034 



—o-oiio 



0.0329 



0-0815 



10 " 



2-0 



33-1 



0-1144 



0-1054 



— 0-0090 



0-0269 



0-0875 



10 " 



2-0 



33-6 



0-1144 



0-1075 



— 0-0069 



0-0208 



0-0936 



