CONTRIBUTIONS FROM THE ROGERS LABORATORY 



OF PHYSICS, MASSACHUSETTS INSTITUTE 



OF TECHNOLOGY. 



LIU. — ON THE EQUILIBRIUM OF THE SYSTEM CONSISTING 



OF LIME, CARBON, CALCIUM CARBIDE AND 



CARBON MONOXIDE. 



By M. deKay Thompson. * 



Presented by H. M. Goodwin, February 9, 1910. Received February 20, 1910. 



1. Introduction. 



"While the author of the following paper was working on the subject 

 indicated in the title above, an article dealing with the same matter 

 appeared in the Electrochemical and Metallurgical Industry. 1 The 

 present writer's results did not agree with those in the article referred 

 to, and it was therefore thought best to publish a preliminary paper on 

 the subject, which was accordingly presented at the October meeting 

 of the American Electrochemical Society in New York. As the work 

 has now been brought to a close, the following article will be made 

 complete, including all of the preliminary publication that is necessary 

 . for clearness. 



According to the Phase Rule 2 the substances taking part in the re- 

 action CaO + 3C ^zt CaC 2 + CO form a monovariant system, that is to 

 say, for any given temperature there is a definite pressure of carbon 

 monoxide which will preserve equilibrium. In order that equilibrium 

 can exist the reaction must be reversible. The fact that this reaction 

 is reversible has been shown by Rothmund 3 and others. 4 Rothmund 

 also attempted to measure the temperature of formation of carbide by 

 heating to different temperatures lime and carbon, and testing the 

 charge immediately afterwards to see if it reacted with water, giving 

 off acetylene. The furnace used consisted of a carbon tube through 



1 C. A. Hansen, Electrochem. Met. Ind. 1909, 7, 427. 



2 See Findlay, "The Phase Rule," p. 16. 



3 Zeitschr. f. anorg. Chem. 1902, 31, 136. 



* A. Frank, Zeitschr. f. angew. Chem. 1905, 44, 1733. 



