Write the order of thermal stability of the hydrides of Group $16$ elements.

Which of the following statements is true for group $16$ elements?

For the preparation of sodium thiosulphate by the "Springs reaction",the reactants used are

How many total statements are correct in the following?
$(i)$ $SO_2$ - antichlor,preservative
$(ii)$ $O_3$ - Disinfectant
$(iii)$ $Cl_2$ - Antiseptic
$(iv)$ $O_2$ - used in oxy-acetylene welding
$(v)$ $PH_3$ - used in smoke screens
$(vi)$ $HNO_3$ - Pickling of stainless steel

Concentrated $H_2SO_4$ reacts with $PCl_5$ to produce

Which of the following is used to absorb sulphur dioxide?