In the brown ring test,the brown color for $NO_2^-$ and $NO_3^-$ is due to the formation of which complex ion?

Which ion's salt solution produces a violet layer when chlorine water and chloroform are added?

When chlorine water is added to an aqueous solution of potassium halide in the presence of chloroform,a violet colour is obtained. On adding more chlorine water,the violet colour disappears,and a colourless solution is obtained. This test confirms the presence of which of the following in the aqueous solution?

The reagent$(s)$ that can selectively precipitate $S^{2-}$ from a mixture of $S^{2-}$ and $SO_4^{2-}$ in aqueous solution is(are):
$(A)$ $CuCl_2$
$(B)$ $BaCl_2$
$(C)$ $Pb(CH_3COO)_2$
$(D)$ $Na_2[Fe(CN)_5NO]$

Which of the statement is incorrect for the given paragraph?
Simple salt $\xrightarrow{\text{Flame test}}$ Golden yellow flame
Simple salt $\xrightarrow[MnO_2]{Conc. H_2SO_4} (X)$ Yellowish green gas
Simple salt $\xrightarrow{AgNO_3} (Z)$ White ppt. (Insoluble in dil. $HNO_3$)
Simple salt $\xrightarrow[Conc. H_2SO_4]{K_2Cr_2O_7} (Y)$ Reddish brown vapour

Which of the following silver precipitates dissolves in $dil. \, HNO_3$ to produce a clear solution?