Litharge is chemically

Among the oxides of nitrogen $N_2O_3$,$N_2O_4$,and $N_2O_5$,the molecule$(s)$ having nitrogen-nitrogen bond is/are

The correct sequence of decrease in the bond angle of the following hydrides is

Consider the following reaction and select the incorrect statement about gas $(P)$:
$Zn + HNO_3 (\text{Dilute}) \to Zn(NO_3)_2 + P \uparrow $

Which among the following oxoacids of phosphorus will have $P-O-P$ bonds?
$I$. $H_4P_2O_5$
$II$. $H_4P_2O_6$
$III$. $H_4P_2O_7$
$IV$. $(HPO_3)_3$

Why is $BiH_{3}$ the strongest reducing agent amongst all the hydrides of Group $15$ elements?