701.

Ionisation potential values of noble gases decrease down the group with increase in atomic size. Xenon forms binary fluorides by the direct reaction of elements. Identify the correct statement(s) from below.

• Only the heavier noble gases form such compounds

• It happens because the noble gases have higher ionisation energies

• It happens because the compounds are formed with electronegative ligands

• Octet of electrons provide the stable arrangements

Assertion: In some cases oxygen shows positive oxidation number though it is an electronegative element.

Reason : Fluorine is more electronegative than oxygen.

• If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

• If both Assertion and Reason are true but Reason is not the correct explanation of Assertion 

• If Assertion is true but Reason is false.

• If Assertion is false but Reason is true.

Assertion: All halogens are coloured.
Reason: The halogens absorb visible light.

• If both assertion and reason are true and the reason is a correct explanation of the assertion.

• If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

Assertion: F-F bond has low bond dissociation energy.
Reason: The fluorine has lower reactivity.

• If both assertion and reason are true and reason is a correct explanation of the assertion.

• If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

Assertion: Dinegative anion of oxygen (O^2-) is quite common but negative anion of sulphur (S^2-) is less common.
Reason: Covalency of oxygen is two.

• If both assertion and reason are true and the reason is a correct explanation of the assertion.

• If both the assertion and reason are true but the reason is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

The number of acidic protons in H₃PO₃ are:

• 0

• 1

• 2

• 3

In the brown ring complex [Fe(H₂O)₅(NO)]SO₄, nitric oxide behaves as:

• NO⁺

• neutral NO molecule

• NO^-

• NO^2-

The hydrides of the first elements in groups 15-17, namely NH₃, H₂O and HF respectively show abnormally high values for melting and boiling points. This is due to

• small size of N, O and F

• the ability to form extensive intermolecular H-bonding

• the ability to form extensive intramolecular H-bonding

• effective van der Waals' interaction

Roasting of sulphides gives the gas X as a by-product. This is a colourless gas with choking smell of burnt sulphur. and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic acts as a reducing agent and its acid has never been insolated. The gas X is

• H₂S

• SO₂

• CO₂

• SO₃

Among the following observations, the correct one that differentiates between SO${}_3^{2-}$ and SO${}_4^{2-}$ is

• both form precipitate with BaCl₂, SO${}_3^{2-}$ dissolves in HCl but SO${}_4^{2-}$ does not

• SO${}_3^{2-}$ forms precipitate with BaCl₂, SO${}_4^{2-}$ does not

• SO${}_4^{2-}$ forms precipitate with BaCl₂, SO${}_3^{2-}$ does not

• both form precipitate with BaCl₂, SO${}_4^{2-}$ dissolves in HCl but SO${}_3^{2-}$ does not