Solid State_XII Flashcards
Polar solids
NH3
HCl
Non-polar solids
I2
CO2
H-bonded solid
Ice
Metallic solid
Pt(s)
Ni(s)
Ag(s)
Covalent solids
Graphite
Diamond
BNx
Crystalline solids are _________iso/aniso-tropic solids.
Anisotropic (diff.physical prop.in diff.directions)
Amorphous solids are isotopic/anisotropic.
Isotropic
Short range properties is a characteristic of
Amorphous solids.
*have range of mp.
Long range property is a characteristic of
Crystalline solid.
Rubber
Neoprene
Melamine
Are examples of _______ solids.
Amorphous
Examples of crystalline solid are
Inorganic benzene SiC SiO2 (silica) Quartz Graphite Diamonds BNx
How many bravis lattices are there
14.
3241121 (teen so chobis gyara so ikkis)
Ctohrmt. *last t = triclinic
A ≠ B ≠C & α ≠ß ≠ gamma represents _____crystal lattice.
Triclinic crystal lattice
Gamma = 120 in
Hexagonal crystal lattice.
A=B ≠C ; α = ß = 90° gamma =120
Rhombohedral crystal lattice is represented as
A=b=c ; α = ß = gamma ≠ 90 °
Tetragonal crystal lattice is
A=B ≠ C ; α = ß = gamma = 90 °
Rank =
Contribution of point x no. Of points
Or points per unit cell
Formula = Ar1 Br2 Cr3 ; r1,r2,r3 are respective ranks.
For fcc touching condition is
4R= √2 a
Pts at face diagonal touch each other.
For bcc touching condition is
4R = √3 a
Pts at body diagonal touch each other.
For scc touching condition is
a= 2R
Corner pts touch each other.
Packing fraction is
(Rank x space occupied by pt.)/ tot. space of unit cell(i.e a³ )
100 - %PF =% Void
True / false.
True
For SCC, %PF & %void is
%PF = 52% = π/6
So, %void = 48%
%PF & % void for FCC is
%PF = 74% = √2 π/6
So, %Void = 26%
Fcc ka fav. No. 2 hai isliye T.C(R)= √2a/4 & %void = 26%
%PF & %void in BCC is
%PF = 68% √3 π/8
So, %void = 32%
Bcc ka fav. No. 3 hai i.e why TC(R)= √3a/4 & %void =32%
Give 1st, 2nd & 3rd CN (coordination no.) for SCC
6, 12, 8
Give 1st, 2nd & 3rd CN (coordination no.) for FCC
12, 6, 24
4th CN = 12
Give 1st, 2nd & 3rd CN (coordination no.) for BCC
8, 6, 12
4th CN = 8
Mass of unit cell =
Mass of unit cell = (At.mass x Rank)/Na
Na = avogadro’s no.
Density of unit cell =
Density = (At. Mass x Rank)/(Na x a³ )
Na= avigadro’s no.
a ³ = volume of unit cell
AB-AB type closed packing is
Hexagonal close packing
%PF = 90%
Rank = 6
CN =12
ABC-ABC type close packing is
3-d close packing similar to fcc maybe ccp or hcp (cn=12)
A-A type close packing is
Square close packing
CN=4
Rank = 1
%PF = 78%
For octahedral void, give relation b/w r+ & r-
r+ = 0.414 r-
For tetrahedral void, give relation b/w r+ & r-
r+ = 0.225 r-
For cubic void, give relation b/w r+ & r-
r+ = 0.732 r-
No. Of OV/cell = 4
No. Of TV/cell = 8
No. Of CV/cell = 1
Identify correct one.
All are correct.
Where ov=octahedral voids
Tv= tetrahedral voids
Cv =cubic void
Shottkey defect is shown by
NaCl KCl CsCl CsBr AgBr
*solids hvng higher CN.
Frankel defect is shown by
ZnS
AgCl
AgBr
AgI
*solids hvng lower CN.
_____ shows both shottkey & frankel defect.
AgBr
F-centre is found in
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.
Metal deficiency defect is shown by
Transition metals
Fe 0.98 O
Fe 0.93 O
Metal excess defect arises due to
A) Anionic vacancy.
B) Presence of extra cations in interstitial sites.
On heating,
ZnO (white) ——> yellow
Due to metal excess defect.
Examples of metal excess defect are
On heating,
NaCl(s) ——> NaCl (yellow)
LiCl (s) ——> LiCl (pink)
KCl ——> KCl (violet)
Examples of paramagnetic substances
TiO VO2 CuO O2 B2 N2+ Cu ++ Fe +++
Diamagnetic substances
Weakly repelled (have paired electrons) TiO2 NaCl ZnCl2 Benzene H2O Ar Ca++ Na+ Ne
Ferromagnetic substances
|| || || All alligned in one direction.
Fe, Co,Ni, CrO2
Anti ferromagnetic
= in parallel & anti-parallel direction
MnO, MnO2, Mn2O3
Ferrimagnetic substances
Unequal up & down
Fe3O4
MgFe2O4
ZnFe2O4
Fe3O4 becomes paramagnetic from ferrimagnetic at ___K.
850 K
I.e high temp.
CN, %PF, Rank of Diamond is
CN= 4 %PF = 34% Rank = 8
Diamond=fcc+50%of tv
Give range of conductors & variation with temp.
10^4- 10^7 ohm inverse meter inverse
T increases Conduction decreases
Range for semi-conductors
10^6 - 10^4 ohm inverse meter inverse
T inc. Conduction inc.
Egs, Si,Ge
Doping increases conduction.
T/F
T for semi-conductors.
Electron rich doping is c/d
N-type
Egs, N,P,As. (Grp 15)
Conduction is due to electronic movement.
Electron deficient doping is c/d
P-type
Egs., B,Al. (Grp 13)
Conduction is due to movement of +ve holes.
