What precipitate is formed when $SnCl_2$ is added to $HgCl_2$?

Given below are certain cations. Using inorganic qualitative analysis,arrange them in increasing group number from $0$ to $VI$.
$A. Al^{3+}$ $B. Cu^{2+}$
$C. Ba^{2+}$ $D. Co^{2+}$
$E. Mg^{2+}$
Choose the correct answer from the options given below:

$(Yellow\,ppt)\,T \xleftarrow{{{K_2}Cr{O_4}}} X$ $\xrightarrow{{dil.\,HCl}} Y(Yellow\,ppt) + Z \uparrow (pungent\,smelling\,gas)$. If $X$ gives green flame test,then $X$ is:

Aqueous solution of Mohr's salt gives the test of which ions?

$A$ black sulphide is formed by the action of $H_2S$ on

$A$ compound is soluble in water. If ammonia is added,a red precipitate appears which is soluble in dilute $HCl$. The compound contains: