Which of the following statements is incorrect for the auto-ionization reaction of ammonia?
$2NH_3 \rightleftharpoons NH_4^+ + NH_2^-$

Equivalent weight of $H_3PO_2$ when it disproportionates into $PH_3$ and $H_3PO_3$ is:

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 $25$)

How many moles of $H_2SO_3$ are required to reduce one mole of $KMnO_4$ in an acidic medium?

$O_3 + 2KI_{(aq)} \rightarrow ?$ The product of the reaction is:

Thiosulphate reacts differently with iodine and bromine in the reactions given below:
$2 S_2 O_3^{2-} + I_2 \rightarrow S_4 O_6^{2-} + 2 I^{-}$
$S_2 O_3^{2-} + 4 Br_2 + 5 H_2 O \rightarrow 2 SO_4^{2-} + 8 Br^{-} + 10 H^{+}$
Which of the following statements justifies the above dual behaviour of thiosulphate?