Give the preparation of a) XeOF₄ b) XeO₂F₂

a) Preparation of XeOF₄: XeOF₄ can be prepared by partial hydrolysis of XeF₆.
${\mathrm{XeF}}_6+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{XeOF}}_4+2\mathrm{HF}$
b) Preparation of XeO₂F₂: XeO₂F₂ can be prepared by partial hydrolysis of XeF₆ 
${\mathrm{XeF}}_6+2{\mathrm{H}}_2\mathrm{O}\to {\mathrm{XeO}}_2 \mathrm{F}2+4\mathrm{HF}$