How is ${\mathrm{XeO}}_3$ prepared from xenon fluorides? Describe the structure of ${\mathrm{XeO}}_3$ on the basis of hybridisation.

Complete the following chemical equations:

${\mathrm{XeF}}_2 + {\mathrm{H}}_2\mathrm{O} \stackrel{ }{\to }$
 

Complete the following chemical equations:

${\mathrm{P}}_4 + \mathrm{NaOH} + {\mathrm{H}}_2\mathrm{O} \stackrel{ }{\to }$
 

Complete the following chemical equations:

$\mathrm{Au} +\mathrm{Cl} \stackrel{ }{\to }$

Explain the following statement:

The stability of $+5$ oxidation state decreases down the group $15$.

Account for the following :

Phosphorus shows variable oxidation states.

 Write the balanced reaction for the preparation of the following acids.

 Orthophosphorous acid
 

Write the balanced reaction for the preparation of the following acids.

 Orthophosphoric acid