Which of the following compounds has the maximum number of oxo groups $(M=O)$?

Which of the following compounds of sulphur does not hydrolyze at room temperature?

Explain the occurrence of group-$16$ elements.

Identify the correct statements from the following:
$i$. Sulphuric acid is manufactured by contact process.
$ii$. $SO_3$ dissolves in $H_2SO_4$ to form pyrosulphuric acid $(H_2S_2O_7)$.
$iii$. $H_2SO_4$ is used in the manufacture of fertilisers such as ammonium sulphate and super phosphate.
$iv$. In the reaction,$S + 2H_2SO_4 (\text{conc.}) \longrightarrow 3SO_2 + 2H_2O$,$H_2SO_4$ is oxidised to $SO_2$.

The incorrect statement among the following is:

Which one among the following has the $S-O-S$ bonding?