Following data is given for the reaction CaCO3(s)CaO(s)+CO2(g)

fH [CaO(s)]=-635.1 kJ mol-1
fH [CO2(g)]=-393.5 kJ mol-1
fH [CaCO3(s)]=-1206.9 kJ mol-1

Predict the effect of temperature on the equilibrium constant of the above reaction.

Given that, 
fH [CaO(s)]=-635.1 kJ mol-1
fH [CO2(g)]=-393.5 kJ mol-1
fH [CaCO3(s)]=-1206.9 kJ mol-1
In the reaction,
CaCO3(s)CaO(s)+CO2(g)
fH=fH [CaO(s)]+fH [CO2(g)]-fH [CaCO3(s)]
 fH=-635.1+(393.5)-(-1206.9)=178.3 kJ mol-1
Because H value is positive, so the reaction is endothermic. Hence, according to Le-Chateleir's principle, reaction will proceed in forward direction on increasing temperature. Thus, the value of equilibrium constant for the reaction increases.