Which of the following is not a general characteristic of equilibria involving physical processes?

(1) Equilibrium is possible only in a closed system at a given temperature

(2) All measurable properties of the system remain constant

(3) All the physical processes stop at equilibrium

(4) The opposing processes occur at the same rate and there is dynamic but stable condition.

3. HINT: At equilibria, rae of forward and backward reaction is equal.

 At the stage of equilibria involving physical processes like melting of ice and freezing of water etc., processes does not stop but the opposite processes i.e., forward and reverse process occur with the same rate.