METHOD FOR MEASURING CARBON DIOXIDE. 



Ill 



out as follows. A known amount, I to 5 milligrams of Na 2 CO 3 

 were weighed out in a small glass vial. This vial with the car- 

 bonate was placed in 2 c.c.~3 c.c. 50 per cent. H 2 SO 4 in the dish, 

 Fig. i, d, and suspended in the bottle over the Ba(OH) 2 . The 

 vial was then tipped so as to allow the H 2 SO 4 to decompose the 

 carbonate, thus liberating all CO 2 from a weighed amount of 

 Na 2 CO 3 . The rate and completeness of absorption of this 

 liberated CO 2 was then tested by titrating the Ba(OH) 2 at dif- 

 ferent intervals of time after decomposition of the carbonate. 

 A typical test was carried out as follows. Ten one milligram 

 lots of Na 2 CO 3 were weighed out in the glass vials as accurately 

 as the balances and weights used would permit. One of the 

 vials was placed in each bottle as described, over 10 c.c. Ba(OH) 2 

 solution. The time when the Na 2 CO 3 was decomposed was 

 noted and titrations made at different intervals thereafter. 

 Controls to determine the amount of CO 2 absorbed from the air 

 in the bottles accompanied the experiment. Results of such an 

 experiment are given in Table II. 



TABLE II. 



Lots of i milligram Na2COs each, decomposed with 50 per cent. H2SO4 in the 

 closed bottle. Ten c.c. of an approximately w/ioo Ba(OH)2 added to each bottle, 

 Temperature 29 C. 



The absorption was evidently very rapid and nearly complete 

 in less than thirty minutes to an hour. The average amount 

 of CO 2 not recovered in this experiment equivalent to about o.i 



