$A$ reagent used to test the presence of $Fe^{2+}$ ion is

$A$ salt reacts with dilute $HCl$ to produce a gas with a pungent smell and yellow crystals. When tested,the salt gives a green flame. With potassium chromate,the salt gives yellow crystals. Therefore,the salt is.......

Which of the following can be used instead of $NH_4Cl$ in the analysis of group $III$ radicals?

Which of the following sulphates is insoluble in water?

Passing $H_2S$ gas into a mixture of $Mn^{2+}, Ni^{2+}, Cu^{2+}$ and $Hg^{2+}$ ions in an acidified aqueous solution precipitates

$(T)$ imparts violet colour $\xrightarrow{compd.\,(U) + conc.\,H_2SO_4}$ $(V)$ Red gas $\xrightarrow{NaOH + AgNO_3}$ $(W)$ Red ppt. $\xrightarrow{NH_3\,soln.}$ $(X)$
$(W)$ Red ppt. $\xrightarrow{dil.\,HCl}$ $(Y)$ white ppt.
$(U)$ $\xrightarrow[\Delta]{NaOH}$ $(Z)$ gas (gives white fumes with $HCl$)?
$(T)$ sublimes on heating
Identify $(T)$ to $(Z).$