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 ammonium sulphide solution is a suitable reagent for the separation of

Consider the following reactions:
$X(aq.) \xrightarrow{K_4[Fe(CN)_6]}$ Chocolate brown ppt.
$X(aq.) \xrightarrow{AgNO_3}$ White ppt. (insoluble in dil. $HNO_3$)
Then $X$ will be:

Aqueous solution of $FeSO_4$ does not produce a precipitate with:

Choose the correct tests with respective observations.
$(A)$ $CuSO_4$ (acidified with acetic acid) $+$ $K_4[Fe(CN)_6]$ $\rightarrow$ Chocolate brown precipitate.
$(B)$ $FeCl_3 + K_4[Fe(CN)_6]$ $\rightarrow$ Prussian blue precipitate.
$(C)$ $ZnCl_2 + K_4[Fe(CN)_6]$,neutralised with $NH_4OH$ $\rightarrow$ White or bluish white precipitate.
$(D)$ $MgCl_2 + K_4[Fe(CN)_6]$ $\rightarrow$ Blue precipitate.
$(E)$ $BaCl_2 + K_4[Fe(CN)_6]$,neutralised with $NaOH$ $\rightarrow$ White precipitate.
Choose the correct answer from the options given below:

The group reagent for the precipitation of group $II$ basic radicals in qualitative analysis is: