Ozone $(O_3)$ belongs to which group of the periodic table?

Write a note on the oxidation state of group-$16$ elements.

Consider the following statements in respect of oxides of sulphur.
$(1)$ In gas phase $SO_2$ molecule is $V$-shaped.
$(2)$ In gas phase $SO_3$ molecule is planar.
$(3)$ $\gamma-SO_3$ is a cyclic trimer.
Which of the above statements are correct?

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 $SO_2$.

When a small amount of $KMnO_4$ is added to concentrated $H_2SO_4$,a green oily compound is obtained which is highly explosive in nature. The compound is:

The incorrect statement among the following is: