Solid, liquid gas

Question 1

Causes of Non- ideality of gas

Answer 1

Vanderwall studied
1. No forces of attraction
2. Volume of gas compared to vessel negligible

Question 2

intermolecular forces

Answer 2

1. Dipole-dipole
2. Ion-dipole
3. dipole-induced dipole
4. id-id
5. hydrogen bonding

Question 3

intramolecular(strong)forces

Answer 3

Ionic, covalent bonding

Question 4

strength of intermolecular forces depends on

Answer 4

polarity. bigger size molecule has stronger imf

Question 5

dipole dipole

Answer 5

PRESENT IN POLAR MOLECULES
difference in electronegativity of a molecule results in one end being partial positive one being partial negative. e.g HCL

Question 6

strength of dipole dipole depends on

Answer 6

size of molecules and e.n difference

Question 7

dipole-induced dipole [DEBYE forces]

Answer 7

{polar-nonpolar}

positive end of a polar molecule attracts mobile e- of nonpolar molecule.both molecules become dipoles

Question 8

instantaneous-induced dipole [LONDON]

Answer 8

attraction between NONPOLAR molecules(weakest force)

momentary force created between instantaneous dipole and induced dipole. (short lived attraction as e- keeps on moving)
>actually present in all molecules

Question 9

factors affecting london forces

Answer 9

1. size of electronic cloud(extent of distribution)
   2.number of atoms(atomic size) increase b.p and forces

Question 10

ion-dipole forces

Answer 10

ion-polar.
hydration of ions.e.g Na+ and H2O, Cl- and H2O

Question 11

order of strength of intermolecular forces

Answer 11

H-bonding>dipole-dipole>Debye forces>London forces

Question 12

hydrogen bonding

Answer 12

partial positive hydrogen and partial negative HIGHLY NEGATIVE such as F, O, N.

20 timmes weaker than a covalent bond

Question 13

solubility of hydrogen bonded molecules

Answer 13

compounds with hydrogen bond are soluble in hydrogen compounds such as
carboxylic acids and alcohols being soluble in water and hydrocarbons insoluble due to being nonpolar and polar nature of water

Question 14

hydrogen bonding in biological compounds

Answer 14

coiling of amino acids form hydrogen bonds in hair, muscles and silk.
>DNA nucleotides have hydrogen bonds between them

Question 15

adhesive action of paints, dyes, glues is due to which type of bonding

Answer 15

Hydrogen bonding

Question 16

vapour pressure and values of compounds

Answer 16

pressure exerted by vapours of liquid in equilibrium with the liquid at a given temperature.

NAME OF COMP VAPOUR
PRESSURE AT 20C
isopentene 580 torr
ethyl ether 442.2
chlorofoam 170
ccl4 87
water 17.54
glycerol 0.00016

Question 17

factors affecting vapour pressure
1. temperature
2. amount of liquid
3. intermolecular forces
4. density/ molecular mass
5. volume of container
6. surface area

Answer 17

1. direct
2. NOT DEPENDANT
3. inverse
4. inverse
   5.NOT DEPENDANT
   6.NOT DEPENDANT

Question 18

method of determining vapour pressure

Answer 18

manometric method

Question 19

molar heat of fusion

Answer 19

amount of heat absorbed when 1 mol of a solid melts into liquid form at melting point and 1atm

Question 20

molar heat of vapourization

Answer 20

amount of heat absorbed when 1 mol of a liquid changed into vapours at boiling point and 1 atm

water’s—-> 40.6 KJmol-1

Question 21

Molar heat of sublimation

Answer 21

amount of heat absorbed when 1 mol of solid sublimes into vapours at a particular temperatue and 1 atm

Question 22

true or false.

heat of s> heat of v> heat of fusion

Answer 22

TRUE.
sublimation greater than vapourisation, which is grreater than fusion

Question 23

uses of liquid crystals

Answer 23

temperature sensors
skin thermograhy for veins, arteries infectioons and tumours
TV displays

Question 24

crystalline solids and amorphous

Answer 24

made up of a unit cell and have three dimensional arrangement
e.g cu, iron, ice, diamnd.

shapeless and no regular arrangement.
e.g glass,plastic,rubbber,glue,wood.
have no sharp melting points.glass can be blown into diff shapes.

you can make an amorphous solid from crystalline by melting and rapid cooling

Question 25

crystals and their classification.[table]
1. cubic
2. tetragonal
3. orthorhombic
4. monoclinic
5. hexagonal
6. rhombohedral
7. triclinic

Answer 25

axes angles examples
1. a=b=c all 90 Fe,Cu,Ag,Au,NaCl

2. a=b=/c all90 NH4br
3. a=/b=/c all 90 iodine, sulphur
4. a=/b=/c a=90,B=/90 sugar, na2so4
5. a=b=/c a=B=90, y=120 graphite
6. a=b=c a=B>90 Al2O3
7. a=/b=/c no angle 90 K2Cr2O7

Question 26

classification of solids.(crystalline)
with properties of ionic solids.

Answer 26

there are four types;
ionic,covalent,metallic and molecular

ionic solids;
>high mp/bp
>high density
>non conductor in solid. but conduct in molten or liquid
>isomorphism and polymorphism
>fast reactions

Question 27

structure of NaCl

Answer 27

face centered cube.
coordination number 6.

each Na+ is surrounded by 6 Cl- and vice versa.

                   Formula unit: 4 NaCl

.each Cl- at corner is shared by 8 unit cells, so 8Cl- x 1/8= 1Cl-
.each Cl- faces 6 and shared by 2 unit cells so,
6Cl- x1/2= 3Cl-
total= 4

Question 28

Anisotropic properties

Answer 28

Anisotropy; Direction dependant

• refractive index
• co efficient of thermal expansion
• electric conductivity
• thermal conductivity