Which of the following oxides will not act as a reducing agent?

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

Which element of group $15$ forms the most basic compound with hydrogen?

Give physical and chemical properties of dinitrogen.

Which element does not show allotropy:

On heating lead $(II)$ nitrate gives a brown gas $'A'$. The gas $'A'$ on cooling changes to a colourless solid $'B'$. Solid $'B'$ on heating with $NO$ changes to a blue solid $'C'$. Identify $'A'$,$'B'$ and $'C'$,write the reactions involved,and draw the structures of $'B'$ and $'C'$.