In an aqueous solution of volume 500 ml, when the reaction of $2{\mathrm{Ag}}^{+} + \mathrm{Cu} \rightleftharpoons {\mathrm{Cu}}^{2+} + 2\mathrm{Ag}$ reached equilibrium the $\left[{\mathrm{Cu}}^{2+}\right]$ was x M. When 500 ml of water is further added, at the equilibrium $\left[{\mathrm{Cu}}^{2+}\right]$ will be