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

Copper turnings when heated with concentrated sulphuric acid will give:

Explain the trends in oxidation states and chemical reactivity of Group $16$ elements.

Select the correct statement regarding sulphur :-

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?

Assertion: The reaction between $SO_2$ and $H_2S$ in the presence of $Fe_2O_3$ catalyst gives elemental sulfur.
Reason: $SO_2$ is a reducing agent.