在\(\rm{K_{2}CrO_{4}}\)的溶液中存在着如下的平衡:\(\rm{2CrO_{4}^{2-}+2H^{+}⇌Cr_{2}O_{7}^{2-}+H_{2}O}\),\(\rm{K=1×10^{14}.}\)若用\(\rm{0.05mol}\) \(\rm{K_{2}Cr_{2}O_{7}}\)配制成\(\rm{1L}\) \(\rm{K_{2}CrO_{4}}\)溶液,其中\(\rm{c(Cr_{2}O_{7}^{2-}) < 10^{-5}mol/L}\),则所配溶液的\(\rm{pH(}\) \(\rm{)}\)