What is produced when white phosphorus is boiled with a strong solution of caustic soda?

It is because of the inability of $ns^{2}$ electrons of the valence shell to participate in bonding that:

Which of the following oxides of nitrogen is isoelectronic with $CO_2$?

When $NH_3$ reacts with $Cl_2$,which of the following statements are correct?
$(a)$ $NCl_3$ is formed when $Cl_2$ is in excess.
$(b)$ $N_2$ is formed when $Cl_2$ is in excess.
$(c)$ $N_2$ is formed when $NH_3$ is in excess.
$(d)$ $NCl_3$ is formed when $NH_3$ is in excess.

$HNO_3 + P_4O_{10} \to 4HPO_3 + X$. $X$ is

Which of the following has the highest number of $P-H$ bonds?