IN GASES: HYDROGEN, CARBONIC OXIDE, AND OXYGEN. 
627 
The re-action between carbonic oxide and oxygen . 
In the first place the question presented itself—Is the action between a small 
quantity of oxygen and an excess of combustible gases always complete, or is it 
possible that a certain number of oxygen molecules may during the moment of 
explosion remain in equilibrium between the attractions of the other molecules around 
them and so remain uncombined \ 
To solve this question a mixture of carbonic oxide with one-third its volume of 
oxygen was fired in a wet eudiometer at 15° C. and under a pressure of 300 millims. 
Carbonic oxide 
75 volumes. 
Oxygen. . 
■ • 25 „ 
Before explosion . 
. , i00 „ 
After explosion . 
75'9 ,, Contraction = 24*1 
After absorption . 
25*1 „ Absorption = 50"8. 
The contraction on explosion was found to be less than the original volume of 
oxygen by '9 volume, and the absorption was found to be more than double the original 
volume of oxygen by '8 volume. Since more carbonic acid was produced than could 
have been formed by the oxygen taken, it was evident that the carbonic oxide must 
have been oxidized to some extent by the steam present in the eudiometer. Now for 
every molecule of cai’bonic oxide so oxidized, a molecule of free hydrogen must be 
liberated, and the place of the decomposed molecule of steam would be filled by the 
volatilization of a molecule of water from the sides of the tube. In this experiment 
the oxygen, if completely consumed, would oxidize 50 volumes of carbonic oxide to 
carbonic acid, but since 50’8 volumes of carbonic acid were formed, "8 volume of 
carbonic oxide must have been oxidized by the steam. This reduction of ‘8 volume of 
steam, producing an equal volume of hydrogen, would make the contraction on explo¬ 
sion ‘8 volume less than it would have been had no such secondary action taken place. 
The observed contraction agreed with this. A repetition of the experiment gave a 
similar result. 
Volume of carbonic oxide = 
„ oxygen = 
Total volume before explosion = 
„ after explosion = 
„ after absorption = 
73-24 
26-76 
100 
74"02 Contraction = 25 '98. 
19"70 Absorption = 54*32. 
Here the volume of carbonic acid formed is more than twice the volume of oxygen 
taken by - 8 volume, and the contraction on explosion is less than the volume of oxygen 
4 l 2 
