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

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

What are the values of X and Y in the above reaction?

1. H₃PO₂, HPO₂  

2. H₃PO₄, PH₃

3. H₂PO₆, PO₃

4. None of the above

Assertion: Phosphorous (V) has a tendency to only gain electrons as it is in its highest oxidation state.

Reason: PCl₅ can act as an oxidizing as well as a reducing agent.

1. Assertion is true and Reason is correct explanation of Assertion.

2. Assertion is true but Reason is not the correct explanation of Assertion.

3. Assertion is true but Reason is false.

4. Both Assertion and Reason are false.

The catalyst that is used in the contact process is:

1. Fe₂O₃

2. Al₂O₃

3. V₂O₅

4. SO₃

The chemical formula of oleum is - 

1. H₂S₂O₈

2. H₂S₂O₇

3. H₃S₂O₆

4. H₂SO₅

The correct order of bond dissociation energy of halogens ${\text{F}}_2, {\mathrm{Cl}}_2, {\mathrm{Br}}_2 \mathrm{and} {\mathrm{I}}_2$ is-

1. F₂ < Cl₂ < Br₂ < I₂

2. I₂ > Br₂ > F₂ > Cl₂

3. Cl₂ > Br₂ < F₂ > I₂

4. I₂ < F₂ < Br₂ < Cl₂

What is the correct sequence of the basic strength hydrides in increasing order?

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​​​​​​​

Assertion: Nitrogen exists as a diatomic molecule and phosphorus as P₄.

Reason: Phosphorus is smaller in size, so it can form P₄.

1. Assertion is true and the Reason is the correct explanation of Assertion.

2. Assertion is true and the Reason is not the correct explanation of Assertion.

3. Assertion is true but the Reason is false.

4. Both Assertion and Reason are false.

Assertion: R₃P = O exists but R₃N = O does not (R = alkyl group).

Reason: Nitrogen doesn't have d orbitals.

1. Assertion is correct and reason is the correct explanation of assertion.

2. Assertion is true but reason is not the correct explanation of assertion.

3. Assertion is true but reason is false.

4. Both assertion and reason are false.

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.