G 14 Chemical Properties

Question 1

Reaction towards oxygen of g14

Existence of SiO2
Nature of dioxide
Nature of monoxide

Answer 1

SiO2 only exists at high temp
CO2, SiO2, GeO2 - acidic and SnO2, PbO2 - amphoteric
CO - neutral; GeO - acidic ;SnO, PbO- amphoteric

Question 2

Reactivity towards water of g14

Answer 2

C, Si, Ge do not react
Sn only reacts with steam
Pb doesn’t react cuz forms a oxide film

Question 3

Reactivity towards halogen of g14

Does c react directly with halogen to form halides?
Ionic halides?
Why does pbi4 not exist?
Heavier metal halides?
Exception in MCl4 hydrolysis

Answer 3

No, except carbon everyone else does.

SnF4 and PbF4. Rest are covalent.

Doesn’t produce enough energy to unpair 6s² e and excite one to higher orbital to have 4 unpaired e-.

MX2.

Only CCl4 cannot be hydrolysed cuz no d orbital to accept lp.

Question 4

Ability to form pπ - pπ multiple bonds?
This allows the formation of what?

Answer 4

C only. No heavier metals- too large for effective overlapping
Allotropes

Question 5

Diamond

Hyb
Strength
Use
MP

Answer 5

sp³
Hardest substance on earth
Sharpening hard tools, making dyes, manufacturing of tungsten filaments
Very high MP due to 3D networking

Question 6

Graphite

Hyb
Str and force
Why does it conduct electricity
Why soft and slippery
Use
Thermodynamics

Answer 6

sp²
Layered str held by van der waals force.
1 e- each str - mobile - conducts electricity
Cleaves easily because of layers hence soft and slippery
Dry lubricant where oil cannot be used (at high temp)
Thermodynamically stable

Question 7

Fullerene

Prep
No of C
Why is it the only pure form of carbon?
Shape
Rings
Hyb
Why does it have aromatic character?
No of vertices
Spherical fullerene in short is known as

Answer 7

Heating of graphite in presence of he and ar
Even no of C upto 350 or above
Smooth str without any dangling bonds
Soccer ball
20 6 membered and 12 5 membered rings
sp²
Delocalisation of e-
60 vertices
Bucky balls

Question 8

∆fH

Answer 8

Graphite =0
Fullerene>diamond