In the manufacture of sulphuric acid by the contact process,the Tyndall box is used to

Determine whether the following statements are True $(T)$ or False $(F)$:
$1.$ $SO_2$ is converted to $SO_3$ in the production of sulfuric acid.
$2.$ Ziegler catalyst is used for the oxidation of $SO_2$ to $SO_3$.

Which one of the following is the correct decreasing order of boiling point?

Given below are two statements: Statement $I$: The covalency of oxygen is generally two but it can exceed up to four. The oxidation state of oxygen in $SO_2$ is $-2$ and in $OF_2$ it is $+2$. Statement $II$: The anomalous behaviour of oxygen when compared to the other elements of group $16$ is due to its small size and high electronegativity. In the light of the above statements,choose the correct answer from the options given below.

Which of the following is used to absorb sulphur dioxide?

When sulphur is boiled with $Na_2SO_3$,a compound $(A)$ is produced. $(A)$ on reaction with excess $AgNO_3$ solution gives a compound $(B)$,which after dissolving in water produces a black coloured sulphide $(C)$. Identify the compound $(A)$,$(B)$ and $(C)$.