For a reversible reaction at a certain temperature when it is at equilibrium or equilibrium has been attained whether physical or chemical, a change in certain variables might change the state of equilibrium. These variables include pressure, volume, concentration and temperature. Due to these changes, a system under equilibrium changes its state in such a manner, i.e., the equilibrium moves in forward direction or backward direction, so that the effect of change is annulled. A gaseous phase endothermic decomposition of phosphorus pentachloride, can be made spontaneous by increasing concentration of `PCl_5`, lowering the pressure and increasing temperature of the system.The change in Gibbs energy, for a reaction at equilibrium, e.g. `PCI_5(g) iff PCI_3(g) + Cl_2(g)`. on addition of an inert gas at constant pressure and then at constant volume respectively are :

Options

A. decrease, no change
B. increase, no change
C. change, no change
D. no change, decrease

Answer

A