Consider the equilibrium: CaCO3(s)⇌CaO(s)+CO2(g). What would happen to the system if more CaCO3 were added?
The answer is nothing would happen. why??
CaCO3(s)⇌CaO(s)+CO2(g)
Write the expression for Keq.
Keq = (CO2). Note that CaO and CaCO3 are solids; therefore, they do not appear in the equation. Changes in those two components have no effect on the equilibrium AS LONG AS THE EQUILIBRIUM HAS SOME (JUST SOME--meaning just 1 molecule) CaCO3 and some CaO.