Which of the following substances is ionic?

Which element is not present in Nessler's reagent?

$P_4O_{10}$ cannot be used to dry $NH_3$ because ..............

The most common minerals of phosphorus are

Arrange the following oxides in the correct order of their acidic character:
$N_2O_3$ $(I)$,$P_2O_3$ $(II)$,$N_2O_5$ $(III)$,$As_2O_3$ $(IV)$

Which of the following statements are correct about the reaction between the copper metal and dilute $HNO_3$?
$(I)$ The principal reducing product is $NO$ gas.
$(II)$ $Cu$ metal is oxidised to $Cu^{2+}$ (aq.) ion which is blue in colour.
$(III)$ $NO$ is paramagnetic and has one unpaired electron in antibonding molecular orbital.
$(IV)$ $NO$ reacts with $O_2$ to produce $NO_2$ which is linear in shape.
Choose the correct statements.