The laboratory test 'tailing of mercury' is used to identify:

The bond dissociation energy of the $E-H$ bond in the $H_2E$ hydrides of group $16$ elements (where $E = O, S, Se, Te$) follows which order?

When $H_2S$ gas is passed through nitric acid,the product is

Which of the following dinegative anions is quite common?

Which process is used for the manufacture of $H_2SO_4$?

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.