Which of the following compounds can produce Rinmann's green with $Co(NO_3)_2$ solution?

Identify the metal $M$ and the precipitate $Z$ in the following reaction sequence:
$MSO_4$ $\xrightarrow{NH_4OH} \downarrow X \text{ (white)}$ $\xrightarrow{NH_4OH \text{ (excess)}} Y$ $\xrightarrow{H_2S} \downarrow Z$

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.

The $V^{-}A$ group precipitate was dissolved in $HNO_3$ and treated with an excess of $NH_4OH$. It gives a white precipitate because of:

Which ion is precipitated by the reagent $NH_4Cl$ and aqueous $NH_3$?

Compound $A$ on borax bead test in reducing flame gives green colour bead. Compound $A$ on treatment with $H_2O_2$ followed by treatment with $Pb(OAc)_2$ gives yellow ppt. The metal ion in the compound $A$ is :