Identify the technique used to know the binding nature of nanomaterials.

Which of the following salts is used in the bead test for the qualitative analysis of inorganic substances?

$A$ chemistry student trying to detect the metallic ion in a salt,makes a paste on a clean platinum wire loop of the salt with concentrated $HCl$. When he takes a small amount of this paste and keeps it in a non-luminous Bunsen flame,the colour of the flame changes to grassy green. He should,therefore,conclude that the metal is

Which of the following gives the chromyl chloride test?

Match List-$I$ with List-$II$ and choose the correct answer from the options given below:

List-$I$ (Name of the test)	List-$II$ (Reaction sequence involved) [$M$ is metal]
$A$. Borax bead test	$I$. $MCO_3$ $\rightarrow MO$ $\xrightarrow[+\Delta]{Co(NO_3)_2} CoO \cdot MO$
$B$. Charcoal cavity test	$II$. $MCO_3$ $\rightarrow MCl_2$ $\rightarrow M^{2+}$
$C$. Cobalt nitrate test	$III$. $MSO_4$ $\xrightarrow[\Delta]{Na_2B_4O_7} M(BO_2)_2$ $\rightarrow MBO_2$ $\rightarrow M$
$D$. Flame test	$IV$. $MSO_4$ $\xrightarrow[\Delta]{Na_2CO_3} MCO_3$ $\rightarrow MO$ $\rightarrow M$

Which of the following statement$(s)$ is (are) correct when a mixture of $NaCl$ and $K_{2}Cr_{2}O_{7}$ is gently warmed with conc. $H_{2}SO_{4}?$