Following data is given for the reaction: CaCO3 (s) → CaO3 (s) + CO2 (g)
ΔfH⊖ [CaO (s)] = -635.1 kJ mol=-1
ΔfH⊖ [CO2 (g)] = -393.5 kJ mol-1
ΔfH⊖ [CaCO3 (s)] = -1206.9 kJ mol-1
Predict the effect of temperature on the Equilibrium constant of the above reaction.
Given; CaCO3 (s) → CaO3 (s) + CO2 (g)
ΔfH⊖ [CaO (s)] = -635.1 kJ mol-1
ΔfH⊖ [CO2 (g)] = -393.5 kJ mol-1
ΔfH⊖ [CaCO3 (s)] = -1206.9 kJ mol-1
We know that,
Where is the standard enthalpy change for the formation of one mole of compound from its elements in their most stable states of aggregation.
= ΔfH⊖ [CaO(s)] + ΔfH⊖ [CO2(g)]- ΔfH⊖ [CaCO3(s)]
= -635.1 -393.5+1206.9
=178.3 kJ mol-1
=positive
i.e. the reaction is exothermic.
Hence according to Le Chatelier’s Principle on increasing the temperature the reaction will shift to forward direction.