Pure $HNO_3$ is a colorless liquid,but it turns light brown in the presence of light. This is due to its decomposition into which of the following substances in small amounts?

Extra pure $N_2$ can be obtained by heating

Small quantities of $NO$ and $HNO_3$ are formed as impurities when $N_2$ is prepared from $NH_4Cl_{(aq)}$ and $NaNO_{2(aq)}$. These impurities can be removed by passing the $N_2$ gas through which of the following?

Regarding the hydrides of group $15$ elements $EH_{3}$ $(E = N, P, As, Sb, Bi)$, select the correct statement from the following:
$A$. The stability of hydrides decreases down the group.
$B$. The basicity of hydrides decreases down the group.
$C$. The reducing character increases down the group.
$D$. The boiling point increases down the group.
Choose the correct answer from the options given below:

Which of the phosphorus oxoacids can create a silver mirror from $AgNO_3$ solution?

Which of the following statements regarding $N_2O_4$ is not correct?