Which of the following match is $INCORRECT$ :

Which of the following pair of cations can be separated by excess $NaOH$ solution?

An aqueous solution contains the ions as $Hg_2^{2+}$,$Hg^{2+}$,$Pb^{2+}$,and $Cd^{2+}$. The addition of dilute $HCl$ $(6 \ N)$ precipitates:

Nessler's reagent is

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:

$A$ is:
$\text{Salt } A \text{ (Colourless)} \xrightarrow{Cu} \text{Blue solution}$
$\text{Salt } A \text{ (Colourless)} \xrightarrow{HCl_{(aq)}} \text{White ppt}$
$\text{Salt } A \text{ (Colourless)} \xrightarrow{\text{Conc. } H_2SO_4} \text{Brown fumes}$