﻿Prof. K. Bun sen on the Washing of Precipitates. 





1 



0' 



1 

 50000 





1 



l 





1 



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10000 



2000(J 



1000C 



I. 



11. 



III. 



I. 



11. 



III. 



I. 



II. 



III. 



I. 



II. 



III. 



V 



n. 



W. 



V 



n. 



W. 



V 



n. 



W. 



V 



n. 



W. 



V 



0-5 







V 







V 



i 



0-5 



244 





V 







28-4 



14-2 



0-5 



267 



13-3 



12-2 



0-5 



227 



114 



1 



16-6 



16-6 



1 



156 



15-6 



1 



14-3 



14-3 



] 



13-3 



13-3 



2 



10-5 



210 



2 



98 



19-7 



2 



90 



18-0 



2 



8-4 



16-8 



3 



8-3 



24-9 



3 



7-8 



234 



3 



71 



21-4 



3 



6-6 



19-9 



4 



71 



28-6 



4 



67 



26 9 



4 



61 



24-6 



4 



5-7 



229 



5 



6-4 



32 1 



5 



60 



30-2 



5 



5 5 



276 



5 



51 



25 7 



6 



5-9 



35 5 



6 



56 



33-4 



6 



5 1 



30-5 



6 



47 



28-4 



7 



5-5 



38-8 



7 



5-2 



36-4 



7 



4-8 



33-3 



7 



4-4 



31-0 



8 



5-2 



42 



8 



4-9 



394 



8 



4-5 



361 



8 



4-2 



33-5 



9 



50 



45 



9 



47 



423 



9 



4 3 



38-7 



9 



40 



36-0 



10 



4-8 



480 



10 



45 



45 1 



10 



41 



41-3 



10 



3-8 



38-4 



11 



4-6 



51-0 



11 



4-4 



47-9 



11 



40 



43 8 



11 



3-7 



40 8 



12 



4-5 



53 9 



12 



42 



50-6 



12 



3-9 



46-3 



12 



3-6 



43-1 



13 



44 



564 



13 



41 



53-3 



13 



3-8 



48-8 



13 



3-5 



45-4 



14 



4-2 



59-4 



14 



40 



55-8 



14 



3-7 



511 



14 



3-4 



475 



15 



42 



62-3 



15 



3-9 



58-5 



15 



3-6 



53-6 



15 



33 



498 



16 



41 



650 



16 



38 



61 1 



16 



3-5 



560 



16 



3-3 



53-0 



17 



40 



67-8 



17 



37 



636 



17 



3-4 



583 



17 



32 



54-2 



18 



3-9 



70-4 , 



18 



37 



6>vl 



18 



34 



60-5 



18 



31 



563 



19 



3-8 



74-3 



,9 



36 



686 



19 



3-3 



62 8 



19 



31 



58-4 



When the washing-process is performed in a beaker, the rela- 

 tion between the volume of the precipitate and that of the liquid 

 may be easily determined by holding a strip of paper along the 

 side of the vessel and marking upon it the respective heights of 

 the precipitate and supernatant liquid ; then on folding the por- 

 tion of paper lying between the two marks in such a manner that 

 each fold corresponds to the height occupied by the precipitate, 

 the number of folds will give the argument in column I. to 

 find in column II. the number of decantations needed to wash 

 to the required extent. If the washing be conducted as in 

 the ordinary method of filtration, funnels possessing an angle 

 of 60° must be invariably employed, and the capacities of the 

 various-sized filters once for all determined by means of a bu- 

 rette. After the precipitate has been brought upon the filter 

 and allowed to drain, it is mixed as thoroughly as possible 

 with water from a graduated washing-flask. Call the amount of 

 water thus necessary to fill the filter t?, and the capacitv of the 



V V . 



empty filter 2?, then ^ = — in column I.; that is, the argu- 

 ment needed to find in column 11. the number of times it is ne- 

 cessary to refill the filter in order to wash the precipitate to the 

 desired extent. 



B2 



