428.    ---------------.[CANTELO, R. C.]  Methane Equilibrium.  I.  Jour. Phys. Chem., vol. 30, 1926, pp. 1641-1645; Chem. Abs., vol. 21, 1927, p. 522.

                  Equilibrium constants for the reaction C+2 H₂=CH₄+21,730 cal., were calculated by Saunders’ equation log K_p=(4583/T)-1.75 log T+0.000630 T-0.7 over the temperature range 500°-1,100°.  With these values of K_p the equilibrium concentrations of CH₄ and H₂ are calculated to be:  Temperature 500°, % CH₄, 63.9; $ H₂, 36.1; 600°, 37.9; 62.1: 700°, 16.3; 83.7: 750°, 13.0; 87.0:800°, 7.5; 92.5: 850°, 4.5; 95.5: 900°, 3.6; 96.4: 1,000°, 2.0; 98.0: 1,100°, 0.8; 99.2.  These values reconcile the results of earlier investigators.  The equilibrium concentrations of CH₄ and H₂ obtained from the catalytic decomposition of pure CH₄ were measured at 565°, 670°, and 770°.  The catalyst was prepared by ignition of pure NiNO₂ deposited on asbestos fibers.  This material was then reduced in H₂.  The gas mixture was circulated over the heated catalyst until no further increase in volume was observed.  The equilibrium composition of the gas was found by analysis to be:  Temperature 565°, % CH₄, 32.7; % H, 58.9; % N₂, 6.5; % CO, 1.4; 670°, 24.4, 68.8, 5.3, 1.9; 770°, 9.2, 85.9, 3.7, 1.2.  The values of K_p corresponding to these results are:  565°, 0.95; 670°, 0.47; 770°, 0.l2.