What is a fusion mixture?

Which of the following gives the chromyl chloride test?

Which of the following solid salt on heating with solid $K_2Cr_2O_7$ and conc. $H_2SO_4$ evolves orange-red vapours that turn an aqueous $NaOH$ solution yellow?

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 one of the following metals will give blue ash when its salt is heated with $Na_2CO_3$ solid and $Co(NO_3)_2$ on a charcoal piece?

Match List-$I$ with List-$II$:

List-$I$ Solid salt treated with dil. $H_2SO_4$	List-$II$ Anion detected
$A.$ Effervescence of colourless gas	$I.$ $NO_2^-$
$B.$ Gas with smell of rotten egg	$II.$ $CO_3^{2-}$
$C.$ Yellowish green gas with pungent and suffocating smell	$III.$ $S^{2-}$
$D.$ Brown fumes	$IV.$ $Cl^{-}$

Choose the correct answer from the options given below: