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 correct increasing order of basic strength of 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

The bonding present in nitrogen molecules is:
1. \(p\pi-p\pi\)
2. \(p\pi-d\pi\)
3. \(d\pi-d\pi\)
4. Only sigma bond

Which of the following is true about reactivity of group 15 elements?

1. Stability of their hydrides increases down the group.

2. Higher oxides are acidic in nature.

3. All elements form pentahalides.

4. They do not react with metals.

The element from group 15 that forms a strong bond with hydrogen is:

The condition that does not exist in the Haber process for the manufacturing of ammonia is:

1. Pressure (around 200 ×10⁵ Pa)
2. Temperature (700 K)
3. Catalyst such as iron oxide.
4. Presence of inert gases.

Number of moles of copper used when

(i) Copper reacts with dilute nitric acid

(ii) Copper reacts with concentrated nitric acid

are respectively:-

1. 1,1

2. 1,3

3. 3,1

4. 3,3