What are the products formed when moist chlorine gas is reacted with hypo?

When $I_2$ is dissolved in $CCl_4$,the color of the solution formed is .....

$Cl_{2(g)} + Ba(OH)_2 \to X (aq.) + BaCl_2 + H_2O$
$X + H_2SO_4 \to Y + BaSO_4$
$Y \xrightarrow[\Delta > 365 \ K]{\Delta } Z + H_2O + O_2$
$Y$ and $Z$ are respectively

Artificial smoke screens are made by

Mercury on heating with aqua-regia gives

With reference to aqua regia,choose the correct option$(s)$.
$(1)$ Reaction of gold with aqua regia produces $NO_2$ in the absence of air.
$(2)$ Aqua regia is prepared by mixing conc. $HCl$ and conc. $HNO_3$ in $3:1$ $(v/v)$ ratio.
$(3)$ Reaction of gold with aqua regia produces an anion having $Au$ in $+3$ oxidation state.
$(4)$ The yellow colour of aqua regia is due to the presence of $NOCl$ and $Cl_2$.