\\\\(XeF_{4} + O_{2}F_{2} \\rightarrow \\underset {(Y)}{XeF_{6}} + O_{2}\\\\).\\\\(XeF_6\\\\) contains \\\\(3\\ lp\\\\) on each \\\\(F\\\\) and \\\\(1\\ lp\\\\) on \\\\(Xe\\\\).Therefore, total number of lone pairs in molecule Y \\\\(= 3\ imes 6 + 1 = 19\\\\)