Given below are some properties. How many of these can hold good for Phosphorus?
($\mathrm{a}$) Metal
($\mathrm{b}$) Non-metal
($\mathrm{c}$) Metalloid
($\mathrm{d}$) Exhibits allotropy
($\mathrm{e}$) Catenation property
($\mathrm{f}$) Solid
($\mathrm{g}$) Good conductor of electricity
($\mathrm{h}$) Least dense among nitrogen family elements.

The reaction sequence below illustrates the various stages of reduction of nitric acid where $\mathrm{a}, \mathrm{b}, \mathrm{c}, \mathrm{d}$ are the number of electrons involved in the reduction of $1$ mole $\mathrm{N}-$atoms.

${\mathrm{HNO}}_3\underset{{\mathrm{ae}}^{-}}{⟶}{\mathrm{NO}}_2\underset{{\mathrm{be}}^{-}}{⟶}\mathrm{NO}\underset{{\mathrm{ce}}^{-}}{⟶}{\mathrm{N}}_2\mathrm{O}\underset{{\mathrm{de}}^{-}}{⟶}{\mathrm{NH}}_3$

Find the value of $(2\mathrm{a}+\mathrm{b}+3\mathrm{c}-\mathrm{d})$.

A yellow coloured crystalline element gives a colourless gas $\left(\mathrm{X}\right)$ on reaction with fluorine which is thermally stable & has octahedral geometry. The atomicity of compound $\left(\mathrm{X}\right)$ would be

Sulphur can form dihalide, tetrahalide and hexahalide with fluorine. One mole of each of these three compounds is mixed with water. The total number of moles of product molecules obtained is              . If no reaction occurs, count zero.

Number of halides undergoing complete reaction in presence of water under normal conditions is :
($i$) ${\mathrm{BF}}_3$
($ii$) ${\mathrm{BCl}}_3$
($iii$) ${\mathrm{NCl}}_3$
($iv$) ${\mathrm{AlCl}}_3$
($v$) ${\mathrm{CCl}}_4$
($vi$) ${\mathrm{PCl}}_3$
($vii$) ${\mathrm{AsCl}}_3$

In how many of the following reactions, ${\mathrm{N}}_2$ gas may be released 
(a) ${\mathrm{NH}}_4{\mathrm{NO}}_2\stackrel{\mathrm{\Delta }}{⟶}$
(b) ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\stackrel{∆}{\to }$
(c) ${\mathrm{NH}}_2{\mathrm{CONH}}_2+{\mathrm{HNO}}_2\stackrel{∆}{\to }$
(d) ${\mathrm{NH}}_2{\mathrm{CONH}}_2+\mathrm{NaOBr}\to$
(e) ${\mathrm{NH}}_3+{\mathrm{Cl}}_2\left(\mathrm{LR}\right)⟶$
(f) ${\mathrm{NH}}_3+{\mathrm{Br}}_2\left(\mathrm{LR}\right)⟶$
(g) ${\mathrm{NH}}_3+\mathrm{NaOCl}⟶$
(h) ${\mathrm{NH}}_3+{\mathrm{CaOCl}}_2⟶$
(i) $\mathrm{Ba}{\left({\mathrm{N}}_3\right)}_2\stackrel{\mathrm{\Delta }}{⟶}$

($i$) ${\mathrm{NH}}_3$
($ii$) ${\mathrm{N}}_2{\mathrm{H}}_4$
($iii$) ${\mathrm{HN}}_3$
($iv$) ${\mathrm{PH}}_3$
($v$) ${\mathrm{H}}_2\mathrm{S}$
($vi$) ${\mathrm{AsH}}_3$
($vii$) ${\mathrm{SbH}}_3$
($viii$) ${\mathrm{H}}_2\mathrm{Se}$
($ix$) ${\mathrm{H}}_2\mathrm{T}e$
The number of molecules in which the lone pair of electrons on the central atom is present in the pure $\mathrm{s}-$orbital.

${\mathrm{NH}}_3+\mathrm{NaOCI}\stackrel{\mathrm{getatin} \mathrm{or} \mathrm{EDTA}}{\to }\mathrm{product}$

The number of moles of $\mathrm{N}-\mathrm{H}$ bond present in one mole of the strongest nucleophile present in the product is :

The number of acidic oxides among the following is :
(a) ${\mathrm{N}}_2\mathrm{O}$
(b) $\mathrm{NO}$
(c) ${\mathrm{N}}_2{\mathrm{O}}_3$
(d) ${\mathrm{N}}_2{\mathrm{O}}_4$
(e) ${\mathrm{N}}_2{\mathrm{O}}_5$
(f) ${\mathrm{P}}_4{\mathrm{O}}_6$
(g) ${\mathrm{P}}_4{\mathrm{O}}_{10}$
(h) ${\mathrm{SO}}_3$
(i) ${\mathrm{B}}_2{\mathrm{O}}_3$
(j) $\mathrm{CO}$