Chlorine acts as a bleaching agent only in the presence of

Which one of the following statements is not correct?

$POCl_3$ is prepared by the reaction of:
$(I)$ $P_4 + SO_2Cl_2 \to$
$(II)$ $P_4 + SOCl_2 \to$
$(III)$ $PCl_5 + SO_2 \to$
$(IV)$ $PCl_5 + C_2H_5OH \to$

What are the products formed when moist chlorine gas is reacted with hypo $(Na_2S_2O_3)$?

Which one of the following is used to remove most of plutonium from spent nuclear fuel?

$Cl_{2}O_{7}$ is the anhydride of