topic3🅱️

Question 1

ionic solid brief

Answer 1

cations and anions held together with strong electrostatic forces of attraction.

high melting and boiling point
hard, brittle
conductive when molten or dissolved in aqueous solution

NaCl eg

Question 2

what is a binary solid

Answer 2

a solid comprised of 2 different elements

Question 3

some binary solids can be what

Answer 3

some binary solids can be molecular or covalent network solids

(SiO2)

Question 4

although some bindery solids can be molecular or covalent network solids,, many binary solids are

Answer 4

IONIC COMPOUNDS

Question 5

binary ionic solids can be described using what

Answer 5

explained as being based on close packed structure types.

Question 6

describe binary ionic solids

Answer 6

close packed array of ions of one element

with ions of the other element located in a proportion of the interstitial sites

Question 7

number of octahedral interstitial sites in CCP // FCC

Answer 7

N

number of atoms in unit cell (based on its contribution)
1/8 x 8 = 1
1/2 x 6 = 3
1 + 3 = 4
SO 4 OCTAHEDRAL INTERSTITIAL

Question 8

number of tetrahedral interstitial sites in a ccp // fcc

Answer 8

8!!!

2N

based on an atoms contribution

Question 9

octahedral interstitial sites in a ccp//fcc

Answer 9

between every atom basically!!
a gap that is bonded to 6 diff atoms (when u expand the unit cell)
one in the centre aswell.

squish the unit cell down and imagine where the gaps are 💗

Question 10

tetrahedral interstitial sites in a ccp // fcc

Answer 10

in each ✝️ face when u look down.

at 1/4 and 3/4 along the z axis

Question 11

NaCl ,, salt,, sodium chloride brief

Answer 11

ccp structure

all octahedral interstitial sites filled

Question 12

NaCl in depth

Answer 12

ccp array of Cl- anions ,, with Na+ cations in ALL octahedral holes

CN of both = 6,, octahedral coordination (the number of the OTHER ion in the structure it’s immediately next to)

Question 13

general rule with size

Answer 13

anions are the larger ones

Question 14

other materials with NaCl structure

Answer 14

group 1 and halides

NaX
LiX

AgCl

Question 15

Fluorite,, CaF2 structure type

Answer 15

ccp structure

all tetrahedral sites filled

no octahedral sites filled

Question 16

Fluorite,,, CaF2 in depth

Answer 16

ccp array of Ca2+ cations with F- anions in all tetrahedral interstitial sites

Cn: Ca2+ is 8 (cubic coordination)
Cn: F- is 4 ( tetrahedral coordination)

Question 17

ccp array of X with Y in interstitial sites

Answer 17

X is in the ccp array (all vertices and all faces)

Y is in either the octahedral sites,, tetrahedral sites,, or both!!

octa = between every 2
terra = 1 in each window 1/4 and 1/3

Question 18

other materials adopting CaF2 structure

Answer 18

BaCl2
BaF2

Question 19

is smt is in a tetrahedral interstitial site,, what is its coordination number

Answer 19

4!!

Question 20

CN of 8 ,, cubic coordination explanation

Answer 20

like a bcc

with one ion in the middle and 8 diff types of ion in a cube around it

seen in CaF2 fluorite

Question 21

what is zinc blende (spheralite) a polymorph of

Answer 21

polymorph of Zns

Question 22

what is zinc blende // spheralite a polymorph of

Answer 22

ZnS

Question 23

describe zinc blende // spheralite (ZnS) briefly

Answer 23

based on ccp
1/2 tetrahedral holes are filled by Zn2+ ions

Question 24

full exp of zinc blende // spheralite

Answer 24

ccp array of S- anions with Zn2+ cations in 1/2 the tetrahedral holes ( 2 at 1/4 and 2 at 3/4)

S- cn = 4,, tetrahedral geometry

Zn2+ cn = 4,, tetrahedral geometry

CuF CuBr CuCl

Question 25

describe cadmium chloride briefly,, CdCl2

Answer 25

ccp array Cd2+ fill half the octahedral holes Cl- take the ccp array (fcc)

Question 26

describe cadmium chloride in detail

Answer 26

ccp array of Cl- ions with Cd2+ cations filling half the octahedral holes Cl- cn = 3,, trigonal pyramidal coordination Cd2+ cn = 6,, octahedral coordination MnCl2 FeCl2

Question 27

describe nickel arsenide briefly

Answer 27

NiAs Ni 2+ As 2- HCP array of As with Ni in all octahedral sites

Question 28

describe nickel arsenide fully

Answer 28

Ni 2+. As 2- hcp array of As 2- Ni 2+ in all octahedral holes As in 0,1 and 1/2 Ni in 1/4 and 3/4 CN = 6 for both,, octahedral

Question 29

briefly describe wurzite

Answer 29

ZnS Zn 2+ S 2- hcp array of S,, Zn in 1/2 tetrahedral holes

Question 30

fully describe wurzite

Answer 30

ZnS S-2 Zn+2 hcp S array at 0,1 and 1/2 Zn 2+ in 1/2 tetra sites,, at 3/8 and 7/8 cn is both 4

Question 31

describe hcp all octahedral,, how many octahedral sites are there

Answer 31

2 octahedral sites fully in one unit cell. anion in hcp array: 0,1 and 1/2 cation at 1/4 and 3/4

Question 32

describe all tetrahedral holes filled for hcp structure

Answer 32

anion in hcp array 0,1 and 1/2 cation where the anions are but at 3/8 and 5/8 on the sides,,,,, and 1/8 and 7/8 in the centre.

Question 33

describe cadmium iodide fully

Answer 33

hcp array of I- Cd 2+ cations in half octahedral holes I- at 0,1 and 1/2 Cd2+ at 1/4 or 3/4 I- : cn = 3 Cd2+ : cn = 6