Which of the following combines with $Fe(II)$ ions to form a brown complex?

Give the disproportionation reaction of $H_3PO_3$.

Which of the following is used to obtain $Ag$ from $AgNO_3$?

Identify the product obtained when excess chlorine reacts with ammonia.

The good reducing nature of $H_3PO_2$ is attributed to the presence of:

Correct statements from the following are: $A$. Nitrogen in oxidation states from $+1$ to $+4$ disproportionates in acid medium. $B$. Nitrogen has the ability to form $d\text{--}p$ multiple bonds with itself and other elements with small size and high electronegativity. $C$. $N$-$N$ single bond is stronger than $P$-$P$ single bond. $D$. Nitrogen has highest density in its group due to small size. $E$. The maximum covalency of nitrogen is four since it has only four valence orbitals for bonding.