In which of the following is the formation of polyanions maximum?

Assertion : Ozone is an allotrope of oxygen.
Reason : Oxygen is a bluish-coloured liquid and in its singlet state,it is paramagnetic.

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 $SO_2$.

Which of the following is not correct?

Which of the elements of group $16$ has the maximum tendency of catenation?

Ozone,when reacts with potassium iodide solution,liberates a certain product which turns starch paper blue. The liberated substance is......