P-block Group 18 - Noble Gases(12th Grade > Chemistry ) Questions and answers for exam Preparation

12th Grade > Chemistry

P-BLOCK GROUP 18 - NOBLE GASES MCQs

Total Questions : 12 | Page 2 of 2 pages

Question 11. The shape and geometry of

X e F_{2}

in vapor phase are respectively:

Bent and tetrahedral
Linear and tetrahedral
Angular and trigonal bipyramidal
Linear and trigonal bipyramidal

Discuss Question

Answer: Option D. -> Linear and trigonal bipyramidal
:
D
Let us look at the ground state valence electronic configuration of Xe and the first excited state:

The Shape And Geometry Of XeF2 In Vapor Phase Are Respective...

So there are 3 lone pairs of electrons and two bond pairs (each unpaired electron shown above will pair with exactly one electron from either of the Fluorine atoms). These orbitals may be assumed to be hybridized correspond to

s p^{3} d

geometry.
The lone pairs occupy three ends of a symmetrical plane while the bond pairs will be axial or perpendicular to the plane containing the 3 electron pairs.
Shape is linear (due to perfect geometry) while the geometry is trigonal bipyramidal. What will be the F – Xe – F bond angle? Yes. It will will be 180 degrees.
The geometry will be like:

Question 12. Xenon Fluorides are best stored in quartz containers – True or False?

True
False
Both a and b are correct.
Helium is peculiarly attracted only to black holes.

Discuss Question

Answer: Option B. -> False
:
B
Xenon Fluorides are stored in Nickel or Monel containers. They cannot be stored in glass containers or quartz containers as they react with

S i O_{2}

as:

2 X e F_{6} (s) + S i O_{2} (s) \to S i F_{4} (s) + 2 X e O F_{4} (s)

2 X e O F_{4} (s) + S i O_{2} (s) \to S i F_{4} (s) + 2 X e O_{2} F_{2} (s)

2 X e O_{2} F_{2} (s) + S i O_{2} (s) \to S i F_{4} (s) + 2 X e O_{3} (s)

Also, the first two reactions may be used to prepare Xenon oxyfluorides. Further, Xenon oxyfluorides can also be prepared by the controlled, partial hydrolysis of Xenon fluorides.
Hydrolysis of