What condition or substance is used to react with white phosphorus (P₄)
to selectively produce phosphorus trioxide (P₂O₃)?

1. Dry ${\mathrm{O}}_2$

2. A mixture of ${\mathrm{O}}_2$ and ${\mathrm{N}}_2$

3. Moist ${\mathrm{O}}_2$

4. ${\mathrm{O}}_2$  in the presence of an aqueous NaO

Which reaction can not be used for the preparation of halogen acid

$\left(A\right)<mspace\; width="1em"></mspace>2KBr<mspace\; width="1em"></mspace>+H_{2}S{O}_4(conc.)<mspace\; width="1em"></mspace>\to K_{2}S{O}_4<mspace\; width="1em"></mspace>+2HBr$
$\left(B\right)<mspace\; width="1em"></mspace>NaCl<mspace\; width="1em"></mspace>+H_{2}S{O}_4(conc.)<mspace\; width="1em"></mspace>\to NaHS{O}_4<mspace\; width="1em"></mspace>+HCl$
$\left(C\right)<mspace\; width="1em"></mspace>NaHS{O}_4<mspace\; width="1em"></mspace>+NaCl<mspace\; width="1em"></mspace>\to N{a}_{2}S{O}_4<mspace\; width="1em"></mspace>+HCl$
$\left(D\right)<mspace\; width="1em"></mspace>Ca{F}_2<mspace\; width="1em"></mspace>+H_{2}S{O}_4(conc.)<mspace\; width="1em"></mspace>\to CaS{O}_4<mspace\; width="1em"></mspace>+2HF$

What is produced when orthophosphoric acid reacts with phosphate rock (fluorapatite)?

1. $\mathrm{Ca}{\left({\mathrm{H}}_2{\mathrm{PO}}_4\right)}_2+{\mathrm{CaF}}_2$                   

2. ${\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+{\mathrm{CaF}}_2+{\mathrm{H}}_2\mathrm{O}$

3. $\mathrm{Ca}{\left({\mathrm{H}}_2{\mathrm{PO}}_4\right)}_2+\mathrm{HF}$                       

4. ${\mathrm{Ca}}_3{\left({\mathrm{PO}}_4\right)}_2+\mathrm{HF}+{\mathrm{H}}_2\mathrm{O}$

Which of the following pairs of molecules have the almost identical bond dissociation energy?

1. F₂ and H₂

2. N₂ and CO

3. F₂ and I₂

4. HF and O₂

${\mathrm{l}}_2$ reacts with aqueous ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ to give ${\mathrm{Na}}_2{\mathrm{S}}_4{\mathrm{O}}_6$ and Nal. The products of the reaction of Cl₂ with aqueous ${\mathrm{Na}}_2{\mathrm{S}}_2{\mathrm{O}}_3$ are:

1.  ${\mathrm{Na}}_2{\mathrm{S}}_4{\mathrm{O}}_6$ + NaCl

2.  ${\mathrm{NaHSO}}_4$ + HCl

3.  ${\mathrm{NaHSO}}_3$ + HCl

4.  ${\mathrm{NaHSO}}_3$ + NaCl

 An oxyacid among the following that contains both P-H and P-P bonds simultaneously is:

1. H₄P₂O₅

2. H₄P₂O₇

3. H₄P₂O₆

4. None of the above

Incorrectly matched characteristic is:

1. S₈: covalent lattice

2. P₄: tetrahedron

3. S₅^2-: zigzag

4. SiO₂: Covalent lattice

The formation of ${\mathrm{PH}}_4^{+}$ is difficult as compared to ${\mathrm{NH}}_4^{+}$ because

1. Lone pair of phosphorous is optically inert.

2. Lone pair of phosphorous resides in almost pure p - orbital.

3. Lone pair of phosphorous resides at sp³ orbital.

4. Lone pair of phosphorous resides in almost pure s - orbital.

The most volatile halogen acid is

1. HF

2. HCl

3. HBr

4. HI

Given below are two statements: