Which of the following oxides does not give any oxyacid in aqueous solution?

Statement $(A)$: Among the oxides of nitrogen, $NO$ and $NO_2$ are paramagnetic.
Statement $(B)$: $NO$ is paramagnetic in the gaseous state and diamagnetic in the liquid state.
The correct answer is:

The number of ions from the following that are expected to behave as oxidising agents is:
$Sn^{4+}$,$Sn^{2+}$,$Pb^{2+}$,$Tl^{3+}$,$Pb^{4+}$,$Tl^{+}$

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

Which is the strongest Lewis base among the following?

Though nitrogen exhibits $+5$ oxidation state,it does not form pentahalide. Give reason.