Equilibrium in a system having two (or) more phases is known as heterogeneous equilibrium. Heterogeneous equilibria often involve pure solids (or) liquids.
Consider the thermal decomposition of calcium carbonate in a closed vessel, the equilibrium constant for this reaction can be written as
CaCO3(s)
Kc =
Since calcium carbonate and calcium oxide are solids, their concentrations remain constant, and hence, their concentration terms in the expression for equilibrium constant can be ignored.
K'c = [CO2] or Kp = pCO2
It shows that at a particular temperature, irrespective of the masses of the two solids Calcium oxide and Calcium carbonate, there is a constant concentration or pressure of Carbon dioxide in equilibrium with calcium oxide and calcium carbonate.
Characteristics of equilibrium:
Equilibrium in a system having two (or) more phases is known as heterogeneous equilibrium. Heterogeneous equilibria often involve pure solids (or) liquids.
Consider the thermal decomposition of calcium carbonate in a closed vessel, the equilibrium constant for this reaction can be written as
CaCO3(s)
Kc =
Since calcium carbonate and calcium oxide are solids, their concentrations remain constant, and hence, their concentration terms in the expression for equilibrium constant can be ignored.
K'c = [CO2] or Kp = pCO2
It shows that at a particular temperature, irrespective of the masses of the two solids Calcium oxide and Calcium carbonate, there is a constant concentration or pressure of Carbon dioxide in equilibrium with calcium oxide and calcium carbonate.
Characteristics of equilibrium: