Le Chatelier's principle is not applicable for which of the following reaction?
The correct option is B Fe (s)+S (s)⇌FeS (s)
Le-Chatelier's principle is not applicable to solid-solid equilibrium.
Their concentration in the Keq expression is taken to be unity. So, no effect of pressure, volume, increasing or decreasing reactant, product species is there on the system.
Every other reaction has species which are in gaseous state.
thus Le-Chatelier's principle is applicable to all other three options except (b)