$A$ gas that cannot be collected over water is

In the dimer of phosphorus pentaoxide $(P_4O_{10})$,what is the correct order of the number of $P-O-P$,$P=O$,and $P-P$ bonds?

$A$ red solid is insoluble in water,but it becomes soluble if a small amount of $KI$ is added to the water. If this red solid is heated in a test tube,it produces a violet-colored vapor and some metallic droplets are observed on the cooler parts of the test tube. This red solid is........

In $P_4O_{10}$,the number of oxygen atoms attached to each phosphorus atom is

Which of the following oxides is amphoteric in character?

In which of the following silicates,only two corners per tetrahedron are shared?
$I$. Pyro silicate
$II$. Cyclic silicate
$III$. Double chain silicate
$IV$. Single chain silicate
$V$. $3D$ silicate
$VI$. Sheet silicate