356 



TABLE 349.— COEFFICIENTS OF DIFFUSION FOR VARIOUS GASES 



AND VAPORS 



Coefficient 

 Gas or vapor diffusing Gas or vapor diffused into Temp. °C of diffusion 



Air Hydrogen .661 



" Oxygen .1775 



Carbon dioxide Air .1423 



" .1360 



" Carbon monoxide .1405 



" " .1314 



Hydrogen .5437 



Methane .1465 



Nitrous oxide .0983 



Oxygen .1802 



Carbon disulfide Air .0995 



Carbon monoxide Carbon dioxide .1314 



Ethylene .101 



" T I vdrogen .6422 



Oxygen .1802 



" .1872 



Ether Air .0827 



" Hydrogen .3054 



Hydrogen Air .6340 



Carbon dioxide .5384 



" monoxide .6488 



Ethane .4593 



Ethylene .4863 



Methane .6254 



Nitrous oxide .5347 



Oxygen .6788 



Nitrogen " .1787 



Oxygen Carbon dioxide .1357 



Hydrogen .7217 



Nitrogen .1710 



Sulfur dioxide Hydrogen .4828 



Water Air 8 .2390 



•' " 18 .2475 



Hydrogen 18 .8710 



TABLE 350.— DIFFUSION OF METALS INTO METALS 



(It 



dt~ dx* 



where x is the distance in direction of diffusion; v, the degree of concentra- 

 tion of the diffusing metal ; /, the time ; k, the diffusion constant = the 

 quantity of metal in grams diffusing through a cm 2 in a day when unit 



difference of concentration (g/cm s ) is maintained between two sides of a layer one cm 



thick. 



SMITHSONIAN PHYSICAL TABLES 



