Solid State_XII

Question 1

Polar solids

Answer 1

NH3

HCl

Question 2

Non-polar solids

Answer 2

I2

CO2

Question 3

H-bonded solid

Answer 3

Ice

Question 4

Metallic solid

Answer 4

Pt(s)
Ni(s)
Ag(s)

Question 5

Covalent solids

Answer 5

Graphite
Diamond
BNx

Question 6

Crystalline solids are _________iso/aniso-tropic solids.

Answer 6

Anisotropic (diff.physical prop.in diff.directions)

Question 7

Amorphous solids are isotopic/anisotropic.

Answer 7

Isotropic

Question 8

Short range properties is a characteristic of

Answer 8

Amorphous solids.

*have range of mp.

Question 9

Long range property is a characteristic of

Answer 9

Crystalline solid.

Question 10

Rubber
Neoprene
Melamine
Are examples of _______ solids.

Answer 10

Amorphous

Question 11

Examples of crystalline solid are

Answer 11

Inorganic benzene 
SiC
SiO2 (silica)
Quartz 
Graphite
Diamonds 
BNx

Question 12

How many bravis lattices are there

Answer 12

14.

3241121 (teen so chobis gyara so ikkis)

Ctohrmt. *last t = triclinic

Question 13

A ≠ B ≠C & α ≠ß ≠ gamma represents _____crystal lattice.

Answer 13

Triclinic crystal lattice

Question 14

Gamma = 120 in

Answer 14

Hexagonal crystal lattice.

A=B ≠C ; α = ß = 90° gamma =120

Question 15

Rhombohedral crystal lattice is represented as

Answer 15

A=b=c ; α = ß = gamma ≠ 90 °

Question 16

Tetragonal crystal lattice is

Answer 16

A=B ≠ C ; α = ß = gamma = 90 °

Question 17

Rank =

Answer 17

Contribution of point x no. Of points

Or points per unit cell

Formula = Ar1 Br2 Cr3 ; r1,r2,r3 are respective ranks.

Question 18

For fcc touching condition is

Answer 18

4R= √2 a

Pts at face diagonal touch each other.

Question 19

For bcc touching condition is

Answer 19

4R = √3 a

Pts at body diagonal touch each other.

Question 20

For scc touching condition is

Answer 20

a= 2R

Corner pts touch each other.

Question 21

Packing fraction is

Answer 21

(Rank x space occupied by pt.)/ tot. space of unit cell(i.e a³ )

Question 22

100 - %PF =% Void

True / false.

Answer 22

True

Question 23

For SCC, %PF & %void is

Answer 23

%PF = 52% = π/6

So, %void = 48%

Question 24

%PF & % void for FCC is

Answer 24

%PF = 74% = √2 π/6
So, %Void = 26%

Fcc ka fav. No. 2 hai isliye T.C(R)= √2a/4 & %void = 26%

Question 25

%PF & %void in BCC is

Answer 25

%PF = 68% √3 π/8 So, %void = 32% Bcc ka fav. No. 3 hai i.e why TC(R)= √3a/4 & %void =32%

Question 26

Give 1st, 2nd & 3rd CN (coordination no.) for SCC

Answer 26

6, 12, 8

Question 27

Give 1st, 2nd & 3rd CN (coordination no.) for FCC

Answer 27

12, 6, 24 4th CN = 12

Question 28

Give 1st, 2nd & 3rd CN (coordination no.) for BCC

Answer 28

8, 6, 12 4th CN = 8

Question 29

Mass of unit cell =

Answer 29

Mass of unit cell = (At.mass x Rank)/Na Na = avogadro’s no.

Question 30

Density of unit cell =

Answer 30

Density = (At. Mass x Rank)/(Na x a³ ) Na= avigadro’s no. a ³ = volume of unit cell

Question 31

AB-AB type closed packing is

Answer 31

Hexagonal close packing %PF = 90% Rank = 6 CN =12

Question 32

ABC-ABC type close packing is

Answer 32

3-d close packing similar to fcc maybe ccp or hcp (cn=12)

Question 33

A-A type close packing is

Answer 33

Square close packing CN=4 Rank = 1 %PF = 78%

Question 34

For octahedral void, give relation b/w r+ & r-

Answer 34

r+ = 0.414 r-

Question 35

For tetrahedral void, give relation b/w r+ & r-

Answer 35

r+ = 0.225 r-

Question 36

For cubic void, give relation b/w r+ & r-

Answer 36

r+ = 0.732 r-

Question 37

No. Of OV/cell = 4 No. Of TV/cell = 8 No. Of CV/cell = 1 Identify correct one.

Answer 37

All are correct. Where ov=octahedral voids Tv= tetrahedral voids Cv =cubic void

Question 38

Shottkey defect is shown by

Answer 38

``` NaCl KCl CsCl CsBr AgBr ``` *solids hvng higher CN.

Question 39

Frankel defect is shown by

Answer 39

ZnS AgCl AgBr AgI *solids hvng lower CN.

Question 40

_____ shows both shottkey & frankel defect.

Answer 40

AgBr

Question 41

F-centre is found in

Answer 41

``` Metal excess defect ## F-centre is the location where extra electron is trapped. It’s responsible for the colour of solid. Aka colour centre/farbenz zentre. ```

Question 42

Metal deficiency defect is shown by

Answer 42

Transition metals Fe 0.98 O Fe 0.93 O

Question 43

Metal excess defect arises due to

Answer 43

A) Anionic vacancy. | B) Presence of extra cations in interstitial sites.

Question 44

On heating, | ZnO (white) ——> yellow

Answer 44

Due to metal excess defect.

Question 45

Examples of metal excess defect are

Answer 45

On heating, NaCl(s) ——> NaCl (yellow) LiCl (s) ——> LiCl (pink) KCl ——> KCl (violet)

Question 46

Examples of paramagnetic substances

Answer 46

``` TiO VO2 CuO O2 B2 N2+ Cu ++ Fe +++ ```

Question 47

Diamagnetic substances

Answer 47

``` Weakly repelled (have paired electrons) TiO2 NaCl ZnCl2 Benzene H2O Ar Ca++ Na+ Ne ```

Question 48

Ferromagnetic substances

Answer 48

|| || || All alligned in one direction. Fe, Co,Ni, CrO2

Question 49

Anti ferromagnetic

Answer 49

= in parallel & anti-parallel direction MnO, MnO2, Mn2O3

Question 50

Ferrimagnetic substances

Answer 50

Unequal up & down Fe3O4 MgFe2O4 ZnFe2O4

Question 51

Fe3O4 becomes paramagnetic from ferrimagnetic at ___K.

Answer 51

850 K I.e high temp.

Question 52

CN, %PF, Rank of Diamond is

Answer 52

``` CN= 4 %PF = 34% Rank = 8 ``` Diamond=fcc+50%of tv

Question 53

Give range of conductors & variation with temp.

Answer 53

10^4- 10^7 ohm inverse meter inverse T increases Conduction decreases

Question 54

Range for semi-conductors

Answer 54

10^6 - 10^4 ohm inverse meter inverse T inc. Conduction inc. Egs, Si,Ge

Question 55

Doping increases conduction. | T/F

Answer 55

T for semi-conductors.

Question 56

Electron rich doping is c/d

Answer 56

N-type Egs, N,P,As. (Grp 15) Conduction is due to electronic movement.

Question 57

Electron deficient doping is c/d

Answer 57

P-type Egs., B,Al. (Grp 13) Conduction is due to movement of +ve holes.