On reaction of $Lead$ $Sulphide$ with dilute nitric acid,which of the following is not formed?

The reaction of nitric oxide with ozone produces which gases?

The number of bridged oxygen atoms present in compound $B$ formed from the following reactions is
$Pb(NO_3)_2 \xrightarrow{673 \ K} A + PbO + O_2$
$A \xrightarrow{\text{Dimerise}} B$

Dilute nitric acid on reaction with $Ag$ liberates

What may be expected to happen when phosphine gas is mixed with chlorine gas?

Nitrogen forms $N_2$,but phosphorus prefers to exist as $P_4$ rather than $P_2$. Which of the following is the reason for this?