Chemistry group 18

Question 1

Helium and Neon are found in minerals such as…?

Answer 1

Pitchblende,Monazite and Cleiveite

Question 2

What are the main causes for group 18’s chemical inertness ?

Answer 2

• Completely filled valence shell
• High ionisation enthalpy
• Positive electron gain enthalpy

Question 3

Neil Bartlett proved what?

Answer 3

He proved that O2 an Xe have similar ionisation enthalpies

Question 4

Physical characteristics of XeF2,XeF4 and XeF6

Answer 4

White crystalline

Question 5

Physical characteristics of XeO3

Answer 5

colourless , explosive solid

Question 6

Physical characteristics of XeOF4

Answer 6

colourless, volatile , liquid

Question 7

Which one in this group is a cryogenic agent?

Answer 7

He

Question 8

1. Botanical gardens
2. air sensitive
3. superconducting magnet, NMR and MRI
4. fluorescent bulb
5. light bulb
6. discharge tubes
7. inert atm
8. diluent in oxygen tanks

Answer 8

1. Ne
2. Ar
3. He
4. Ne
5. Ar
6. Ne
7. Ar
8. He

Question 9

What happens to atomic radius, boiling point , melting point and ionisation enthalpy down a group.

Answer 9

The first three increase, I.E. decreases

Question 10

Electron gain enthalpy trend down the group

Answer 10

Ne> Ar=Kr> Xe>Rn>He ( He comes to the back, everything else remains the same)

Question 11

Density trend down the group

Answer 11

Rn>Xe>Kr>Ar=He>Ne (He and Ne switch places)

Question 12

structures of the following

1. XeF2
2. XeF4
3. XeF6
4. XeOF4
5. XeO3

Answer 12

1. Linear
2. Square Planar
3. Distorted Octahedral
4. Square pyramidal
5. Pyramidal