Nitrous oxide $(N_2O)$:

Orthophosphorus acid on disproportionation gives $PH_3$ and another oxoacid of phosphorus '$X$'. The basicity of $X$ is

The total number of paramagnetic gaseous products formed in all the following reactions $[A + B + C ]$:
$(A)\ NH_4 NO_3 \xrightarrow{\Delta} \text{Products}$
$(B)\ 3 NaNO_2 + 3 H_2 SO_4 \longrightarrow \text{Products}$
$(C)\ Pb(NO_3)_2 \xrightarrow{673 \ K} \text{Products}$

Given below are two statements $:$
Statement $I :$ Nitrogen forms oxides with $+1$ to $+5$ oxidation states due to the formation of $p\pi-p\pi$ bond with oxygen.
Statement $II :$ Nitrogen does not form halides with $+5$ oxidation state due to the absence of $d$-orbital in it.
In the light of given statements,choose the correct answer from the options given below.

Which one of the following can be used as an anaesthetic?

Cyclic polymetaphosphates have the general formula of $[P_nO_{3n}]^{n-}$. Cyclic trimeric polymetaphosphate $(P_3O_9)^{3-}$ has commercial importance. Which of the following is not true regarding $P_3O_9^{3-}$?