At 143K, the reaction of ${\mathrm{XeF}}_4 \mathrm{with} {\mathrm{O}}_2{\mathrm{F}}_2$ produces a Xenon compound Y. The total number lone pair(s) of electron present on the whole molecule of Y is___

$Xe{F}_4+O_2{F}_2\to Xe{F}_6+O_2$

Shape of $Xe{F}_6$ is distorted octahedral contain one lone pair electrons on central atom 3 lone pair electrons  on each F atom surrounded by Xe.

Total number of lone pairs: 1 + 18 = 19.00