Which of the following gives the chromyl chloride test?

Which of the following solid salt on heating with solid $K_2Cr_2O_7$ and conc. $H_2SO_4$ evolves orange-red vapours that turn an aqueous $NaOH$ solution yellow?

Identify the technique used to know the binding nature of nanomaterials.

Match List-$I$ with List-$II$:

List-$I$ Solid salt treated with dil. $H_2SO_4$	List-$II$ Anion detected
$A.$ Effervescence of colourless gas	$I.$ $NO_2^-$
$B.$ Gas with smell of rotten egg	$II.$ $CO_3^{2-}$
$C.$ Yellowish green gas with pungent and suffocating smell	$III.$ $S^{2-}$
$D.$ Brown fumes	$IV.$ $Cl^{-}$

Choose the correct answer from the options given below:

Assign $A$,$B$,$C$,$D$ from the given type of reaction.
$2KI + FeCl_2 \longrightarrow$ No reaction

Assign $A, B, C, D$ from the given type of reaction.
$Na_2CO_3 + KNO_3 \longrightarrow$ No reaction