\\\\(NaCl\\\\) and \\\\(KCl\\\\) are the salts of a strong acid and strong base. They do not undergo hydrolysis. Their aqueous solutions are neutral.\\\\(Na_2CO_3\\\\) is basic due to hydrolysis of \\\\(CO_3^{2-}\\\\) ion\\\\(CO_3^{2-}+H_2O\\rightleftharpoons HCO_3^-+OH^-\\\\)Hence, \\\\(Na_2CO_3\\\\) will give highest pH in water.