How are XeF₂ , XeF₄ and XeF₆ Prepared ?

XeF₂: XeF₂ is prepared by heating Xe and F₂ in 1:3 ratio in a nickel vessel at 673K and 1 bar pressure.
$\mathrm{Xe}+{\mathrm{F}}_2\underset{1 \mathrm{Bar}}{\overset{673\mathrm{K}}{\to }}{\mathrm{XeF}}_2$
XeF₄: XeF₄ is prepared by heating and in 1:5 ratio in a nickel vessel at 873K and 7 bar pressure.
$\mathrm{Xe}+2{ \mathrm{F}}_2\underset{7 \mathrm{Bar}}{\overset{873\mathrm{K}}{\to }}{\mathrm{XeF}}_4$
XeF₆: XeF₆ is prepared by heating Xe and F₂ in 1:20 ratio in a nickel vessel at 600K and 60-70 bar pressure.
$\mathrm{Xe}+3{ \mathrm{F}}_2\underset{60-70 \mathrm{Bar}}{\overset{600 \mathrm{K}}{\to }}{\mathrm{XeF}}_6$