Which of the following compounds gives a mixture of `SO_(2)` and `SO_(3)` on heating ?

Which of the following compounds is formed when a mixture of K_(2)Cr_(2) O_(7) and KCl is heated with conc. H_(2)SO_(4) ?

Which of the following compound gives yellowish white turbidity with dil. H_(2)SO_(4) ?

Which of the following metal sulphate will give SO_(2) and SO_(3) both gaseous product on heating?

Which one of the following compounds gives aspirin on reacting with acetic anhydride in the presence of cone H_(2)SO_(4) ?