Which of the following is used to prepare $Cl_2$ gas at room temperature from concentrated $HCl$?

What is the shape of an interhalogen compound where the central halogen exhibits a $+3$ oxidation state?

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

Which one of the following is formed apart from sodium chloride when chlorine reacts with hot concentrated sodium hydroxide?

What are $X$ and $Y$ in the given reactions?
$2X_{2(g)} + 2H_2O_{(l)} \to 4H^{+}_{(aq)} + 4X^{-}_{(aq)} + O_{2(g)}$
$Y_{2(g)} + H_2O_{(l)} \to HY_{(aq)} + HOY_{(aq)}$

$Na_2S_2O_3 \cdot 5H_2O$ is used in photography to