Molten iron-carbon solution is in equilibrium with CO-CO2 gas mixture. Calculate the carbon activities in liquid iron for the following compositions at 1833 K. Please indicate the standard state for carbon in your answers:-

Given

(l) P²co/Pc02 ratio in the gas mixture in equilibrium with iron-carbon melt as a function of the carbon concentration at 1833 K:

%C	0.15	0.36	O .49	0.60	0.79	0.88	1.02
P2co/Pc02 (MPa)	10. I	20.6	29.9	41.2	51.5	66.7	80.8

(2) Equilibrium constant K for the reaction

+ C02 - 2CO, log K = -8199/T + 8.66