Group-18 Elements - Free MCQ Practice Test with solutions, NEET Chemistry

Correct option: C.

XeF₂ is an oxidizing and fluorinating agent, not a reducing agent; hence the statement that it is a powerful reducing agent is incorrect.

2 XeF₂ + 2 H₂O → 2 Xe + 4 HF + O₂

This hydrolysis shows Xe(+2) is reduced to Xe(0) while oxygen in water is oxidized to O₂; therefore XeF₂ acts as an oxidizing agent in this reaction.

Structure and bonding: Xenon in XeF₂ has two bond pairs (to F) and three lone pairs, giving a linear molecular shape (VSEPR type AX₂E₃).

Preparation: It is prepared by direct combination Xe + F₂ → XeF₂ under suitable conditions (for example, UV irradiation or electric discharge at elevated pressure), so the synthesis statement is correct.

Therefore, the incorrect statement is option C.

Balance chemical equation for the above two reactions are:

(A) 6XeF₄​ + 12H₂​O ⟶ 4Xe + 2XeO₃ ​+ 24HF + 3O₂​

(B) XeF₆​ + 3H₂​O ⟶ XeO₃​ + 6HF

So, (i) = 24HF; (ii) = 3O₂​ and (iii) = XeO_3​

Hybridization of an atom is identified by caliculating the sum of sigma bonds and lone pairs.

If sum of sigma bonds and lone pairs is 2. sp hybridization

If sum of sigma bonds and lone pairs is 3. sp² hybridization

If sum of sigma bonds and lone pairs is 4. sp³ hybridization.XeO₃​ has 3 sigma bonds and 1 lone pair.So the sum is 4.So it is sp³

If sum of sigma bonds and lone pairs is 5. sp³d hybridization.XeOF_2​ has 3 sigma bonds and two lone pairs ,the sum is 5.So it is SP³d.

If sum of sigma bonds and lone pairs is 6 .sp³d² hybridization.XeF₄​ has 4 sigma bonds and 2 lone pair.So the sum is 6.So it is sp³d²

If sum of sigma bonds and lone pairs is 7. sp³d² hybridization.XeF₆​ has 6 sigma bonds and 1 lone pair. So the sum is 7.So it is sp³d³

So the option A is correct match.

XeF₂​ has a linear shape. Its hybridization is sp³d which means it should have a trigonal bipyramidal shape. Since it has 3 lone pairs, they occupy the equatorial triangle.
XeF₄​ has sp³d² hybridization. It has a square planar shape and 2 lone pair of electrons.
XeF₆​ has one lone pair of electrons. The 6 out of 8 electrons of Xenon are shared by 6 atoms of fluorine.

On hydrolysis the products formed are XeO₃ and HF.
XeF₆ + 3H₂O → XeO₃ + 6HF

Helium is used in filling tubes of aeroplane tyres.

Air is also the most important source for the other noble gases.T races of krypton are found in various minerals, the most important source of Krypton is Earth's atmosphere. Helium obtained from natural gas and radon is obtained as a byproduct during radioactive disintegration.

So Rn is obtained during radioactive disintegration not Kr.

So Krypton is obtained during radioactive disintegration is the wrong statement.