The disproportionation reaction of ${\mathrm{H}}_3{\mathrm{PO}}_3$ is as follows:

${\mathrm{H}}_3{\mathrm{PO}}_3$ $\stackrel{∆}{\to }$ $\mathrm{X}$ $+$ $\mathrm{Y}$

 X and Y in the above reaction are:

1. H₃PO₂, HPO₂  

2. H₃PO₄, PH₃

3. H₂PO₆, PO₃

4. None of the above.

The catalyst that is used in the contact process is:

Which of the following represents the correct chemical formula of oleum?

The correct order of bond dissociation energy of halogens ${\text{F}}_2,<mspace\; width="1em"></mspace>{\mathrm{Cl}}_2,<mspace\; width="1em"></mspace>{\mathrm{Br}}_2<mspace\; width="1em"></mspace>\mathrm{and}<mspace\; width="1em"></mspace>{\mathrm{I}}_2$ is-

1. F₂ < Cl₂ < Br₂ < I₂

2. I₂ > Br₂ > F₂ > Cl₂

3. Cl₂ > Br₂ < F₂ > I₂

4. I₂ < F₂ < Br₂ < Cl₂

Which of the following represents the correct increasing order of basic strength of the Group 15 hydrides?
1. BiH₃ \(\simeq \) SbH₃ < AsH₃ < PH₃ < NH₃ 
2.  BiH₃  > NH₃  > PH₃ > SbH₃ > AsH₃ 
3. SbH₃ < AsH₃ < PH₃ < NH₃ < BiH₃ 
4. AsH₃ > NH₃ > PH₃ > SbH₃ > BiH₃

Lead nitrate upon heating gives:

1. N₂O, PbO
2. NO₂,PbO
3. NO,PbO
4. NO,PbO₂

Which of the following elements does not exhibit allotropy?
1. Nitrogen
2. Phosphorus
3. Antimony
4. Arsenic

What is the maximum covalency exhibited by nitrogen?
1.Three (3)
2.Five (5)
3. Four (4)
4. Six (6)

Which of the following statements is false?