When hypo solution is added to cupric sulphate solution,the blue colour of the latter is discharged,due to the formation of:

Consider the following reaction:
$MnO_2 + KOH + O_2 \rightarrow A + H_2O$
Product '$A$' in neutral or acidic medium disproportionates to give products '$B$' and '$C$' along with water. The sum of spin-only magnetic moment values of '$B$' and '$C$' is . . . . . $BM$. (nearest integer)
(Given atomic number of $Mn$ is $25$)

Assign $A, B, C, D$ from the given type of reaction.
$NO + NO_2 \xrightarrow{-11 \ ^{\circ}C} N_2O_3$

Which of the following is a true statement?

Balance the following equations in basic medium by the ion-electron method and identify the oxidising agent and the reducing agent.
$(a)$ $P_{4(s)} + OH^{-}_{(aq)} \rightarrow PH_{3(g)} + H_{2}P{O_{2}}^{-}_{(aq)}$
$(b)$ $N_{2}H_{4(l)} + Cl{O_{3}}^{-}_{(aq)} \rightarrow NO_{(g)} + Cl^{-}_{(g)}$
$(c)$ $Cl_{2}O_{7(g)} + H_{2}O_{2(aq)} \rightarrow Cl{O_{2}}^{-}_{(aq)} + O_{2(g)} + H^{+}_{(aq)}$

$Na_2S_2O_3$ is