Which compound gives a black color with $NH_4OH$?

Which of the following is not precipitated as sulphide by passing $H_2S$ in the presence of concentrated $HCl$?

In the group analysis of cations, $Ba^{2+}$ and $Ca^{2+}$ are precipitated respectively as

An aqueous solution of a salt $X$ turns blood red on treatment with $CNS^{-}$ and blue on treatment with $K_4[Fe(CN)_6]$. $X$ also gives a positive chromyl chloride test. The salt $X$ is

The colour of $Mg(OH)_2$ precipitate formed when it is precipitated in the presence of magneson reagent is

$A$ precipitate of ....... would be obtained on adding $HCl$ to a solution of $(Sb_2S_3)$ in yellow ammonium sulphide.