States of Matter Notes - Class 11 PDF Download

 Page 1


73 
 
CHAPTER 5 
STATES OF MATTER 
1. Change in state : It is over all effect of Intermolecular 
forces, molecular  Interactional energy & thermal energy: 
2. Measurable properties of gases : P,V, T, n, Viscosity, 
specific heat  are some measurable properties. 
3. Gas Laws : The quantitative relationship b/w any two of 
the variables (V, n, P,T) when other two are constant. 
4. Boyle’s Law : The pressure of fixed msss of gas varies 
inversely with the volume at constant T. P a 1/V(n,T const.) 
P
1
V
1
 = P
2 
V
2
 
5. Charle’s Law : At constant P, the volume of fixed amount 
of gas varies directly with its absolute temperature.  
V a T    or     
2
2
1
1
, tan
T
V
T
V
t cons
T
V
 
6. Gay lussac’s Law : At constant V, The pressure of fixed 
amount of gas varies directly with its absolute temperature. 
P a T     or   
2
2
1
1
,
T
P
T
P
const
T
P
 
7. Ideal gas equation  : The relationship b/w P, V and T by 
Gas Laws  PV= nRT. 
8. Avogadro’s Law : At given T and P, the volume of gas 
varies directly to the amount of gas .   V a n ( P, T constant) 
9. Dalton’s Law of partial persure :  The pressure enerted by a 
mixture of non reacting gases is equal to the sum of their 
partial pressure at constant (V,T) 
Page 2


73 
 
CHAPTER 5 
STATES OF MATTER 
1. Change in state : It is over all effect of Intermolecular 
forces, molecular  Interactional energy & thermal energy: 
2. Measurable properties of gases : P,V, T, n, Viscosity, 
specific heat  are some measurable properties. 
3. Gas Laws : The quantitative relationship b/w any two of 
the variables (V, n, P,T) when other two are constant. 
4. Boyle’s Law : The pressure of fixed msss of gas varies 
inversely with the volume at constant T. P a 1/V(n,T const.) 
P
1
V
1
 = P
2 
V
2
 
5. Charle’s Law : At constant P, the volume of fixed amount 
of gas varies directly with its absolute temperature.  
V a T    or     
2
2
1
1
, tan
T
V
T
V
t cons
T
V
 
6. Gay lussac’s Law : At constant V, The pressure of fixed 
amount of gas varies directly with its absolute temperature. 
P a T     or   
2
2
1
1
,
T
P
T
P
const
T
P
 
7. Ideal gas equation  : The relationship b/w P, V and T by 
Gas Laws  PV= nRT. 
8. Avogadro’s Law : At given T and P, the volume of gas 
varies directly to the amount of gas .   V a n ( P, T constant) 
9. Dalton’s Law of partial persure :  The pressure enerted by a 
mixture of non reacting gases is equal to the sum of their 
partial pressure at constant (V,T) 
74 
 
P (total ) = P1 + P2 + P3 + ………. (T, V, constant) 
10. Kinetic Molecular theory :  
a. Gases consist of large number of identical particles 
(atoms or molecules) that are so small that the actual 
volume of the molecules is negligible in comparison to 
the empty space between them.  
b. There is no force of attraction between the particles of a 
gas at ordinary temperature and pressure  
c. Particles of a gas are always in constant and random 
motion 
d. Pressure is exerted by the gas as a result of collision of 
the particles with the walls of the container 
e. Collisions of gas molecules are perfectly elastic 
f. At any particular time, different particles in the gas have 
different speeds and hence different kinetic energies 
g. Average kinetic energy of the gas molecules is directly 
proportional to the absolute temperature 
11. Real Gases : The gases which deviates from Ideal behavior 
at higher pressure and low temperature b/c of force of 
attraction b/w molecules increases . 
12. Compressibility factor (Z) : It determine extent of devation 
of real gases from Ideal gas behavior : Z = 
. . . T R n
PV
  for ideal 
gas Z=1, for Nonideal gas Z< 1, Z > 1 
13. Vander waal’s Equation : .
2
2
nRT nb V
V
a n
P 
14. Critical Temperature : (Tc) The temperature above which a 
gas cannot be liquefied whatever high pressure may be 
15. Critical Pressure : The minimum pressure required to liquity 
a gas at its critical temperature. 
16. Critical Volume : The volume of 1 mole of gat at Tc, Pc. 
17. Super cooled liquids : The liquids which are cooled to a 
temperature below its freezing point without freezing . 
Page 3


73 
 
CHAPTER 5 
STATES OF MATTER 
1. Change in state : It is over all effect of Intermolecular 
forces, molecular  Interactional energy & thermal energy: 
2. Measurable properties of gases : P,V, T, n, Viscosity, 
specific heat  are some measurable properties. 
3. Gas Laws : The quantitative relationship b/w any two of 
the variables (V, n, P,T) when other two are constant. 
4. Boyle’s Law : The pressure of fixed msss of gas varies 
inversely with the volume at constant T. P a 1/V(n,T const.) 
P
1
V
1
 = P
2 
V
2
 
5. Charle’s Law : At constant P, the volume of fixed amount 
of gas varies directly with its absolute temperature.  
V a T    or     
2
2
1
1
, tan
T
V
T
V
t cons
T
V
 
6. Gay lussac’s Law : At constant V, The pressure of fixed 
amount of gas varies directly with its absolute temperature. 
P a T     or   
2
2
1
1
,
T
P
T
P
const
T
P
 
7. Ideal gas equation  : The relationship b/w P, V and T by 
Gas Laws  PV= nRT. 
8. Avogadro’s Law : At given T and P, the volume of gas 
varies directly to the amount of gas .   V a n ( P, T constant) 
9. Dalton’s Law of partial persure :  The pressure enerted by a 
mixture of non reacting gases is equal to the sum of their 
partial pressure at constant (V,T) 
74 
 
P (total ) = P1 + P2 + P3 + ………. (T, V, constant) 
10. Kinetic Molecular theory :  
a. Gases consist of large number of identical particles 
(atoms or molecules) that are so small that the actual 
volume of the molecules is negligible in comparison to 
the empty space between them.  
b. There is no force of attraction between the particles of a 
gas at ordinary temperature and pressure  
c. Particles of a gas are always in constant and random 
motion 
d. Pressure is exerted by the gas as a result of collision of 
the particles with the walls of the container 
e. Collisions of gas molecules are perfectly elastic 
f. At any particular time, different particles in the gas have 
different speeds and hence different kinetic energies 
g. Average kinetic energy of the gas molecules is directly 
proportional to the absolute temperature 
11. Real Gases : The gases which deviates from Ideal behavior 
at higher pressure and low temperature b/c of force of 
attraction b/w molecules increases . 
12. Compressibility factor (Z) : It determine extent of devation 
of real gases from Ideal gas behavior : Z = 
. . . T R n
PV
  for ideal 
gas Z=1, for Nonideal gas Z< 1, Z > 1 
13. Vander waal’s Equation : .
2
2
nRT nb V
V
a n
P 
14. Critical Temperature : (Tc) The temperature above which a 
gas cannot be liquefied whatever high pressure may be 
15. Critical Pressure : The minimum pressure required to liquity 
a gas at its critical temperature. 
16. Critical Volume : The volume of 1 mole of gat at Tc, Pc. 
17. Super cooled liquids : The liquids which are cooled to a 
temperature below its freezing point without freezing . 
75 
 
18. Elastic Collision : The collisions in which no loss of K.E. 
only there is transfer of energy. 
19. Vapour pressure : The equilibrium pressure by vapour of 
liquid in a container at given temperature (T) 
20. At higher altitude : The b.p. of water decreases b/c the 
atmospheric pressure is less than one atmosphere. 
21. Surface Tension  (V) : It is force acting per unit length 
perpendicular to the line drawn on the surface : (Nm
-1
) :  It 
decreases with increases in T, it increases with increase in 
external pressure, b/c of it falling drops of liquid are 
spherical, liquid in capillary tube rises.   
22. Viscosity (?) : It is resistance offered to the flow of liquid 
due to friction b/w layer of  fluids . 
dn
dv
A n F . . 
23. Effect of T & P on viscosity  : It decreases with increase in 
T, and increases with increase in P. 
24. Low M.P. & B.P. of molecular liquids is due to low 
magnitude of molecular interaction energy. 
One mark questions 
1. At what condition surface tension vanishes ? 
2. Why Helium is used in balloons in place of hydrogen? 
3. At what temperature below which a gas does not obey ideal 
gas law? 
4. At what temperature the volume of a gas is supposed to be 
zero? 
5. What is the molar volume at 0
o
C and 1 bar pressure? 
Page 4


73 
 
CHAPTER 5 
STATES OF MATTER 
1. Change in state : It is over all effect of Intermolecular 
forces, molecular  Interactional energy & thermal energy: 
2. Measurable properties of gases : P,V, T, n, Viscosity, 
specific heat  are some measurable properties. 
3. Gas Laws : The quantitative relationship b/w any two of 
the variables (V, n, P,T) when other two are constant. 
4. Boyle’s Law : The pressure of fixed msss of gas varies 
inversely with the volume at constant T. P a 1/V(n,T const.) 
P
1
V
1
 = P
2 
V
2
 
5. Charle’s Law : At constant P, the volume of fixed amount 
of gas varies directly with its absolute temperature.  
V a T    or     
2
2
1
1
, tan
T
V
T
V
t cons
T
V
 
6. Gay lussac’s Law : At constant V, The pressure of fixed 
amount of gas varies directly with its absolute temperature. 
P a T     or   
2
2
1
1
,
T
P
T
P
const
T
P
 
7. Ideal gas equation  : The relationship b/w P, V and T by 
Gas Laws  PV= nRT. 
8. Avogadro’s Law : At given T and P, the volume of gas 
varies directly to the amount of gas .   V a n ( P, T constant) 
9. Dalton’s Law of partial persure :  The pressure enerted by a 
mixture of non reacting gases is equal to the sum of their 
partial pressure at constant (V,T) 
74 
 
P (total ) = P1 + P2 + P3 + ………. (T, V, constant) 
10. Kinetic Molecular theory :  
a. Gases consist of large number of identical particles 
(atoms or molecules) that are so small that the actual 
volume of the molecules is negligible in comparison to 
the empty space between them.  
b. There is no force of attraction between the particles of a 
gas at ordinary temperature and pressure  
c. Particles of a gas are always in constant and random 
motion 
d. Pressure is exerted by the gas as a result of collision of 
the particles with the walls of the container 
e. Collisions of gas molecules are perfectly elastic 
f. At any particular time, different particles in the gas have 
different speeds and hence different kinetic energies 
g. Average kinetic energy of the gas molecules is directly 
proportional to the absolute temperature 
11. Real Gases : The gases which deviates from Ideal behavior 
at higher pressure and low temperature b/c of force of 
attraction b/w molecules increases . 
12. Compressibility factor (Z) : It determine extent of devation 
of real gases from Ideal gas behavior : Z = 
. . . T R n
PV
  for ideal 
gas Z=1, for Nonideal gas Z< 1, Z > 1 
13. Vander waal’s Equation : .
2
2
nRT nb V
V
a n
P 
14. Critical Temperature : (Tc) The temperature above which a 
gas cannot be liquefied whatever high pressure may be 
15. Critical Pressure : The minimum pressure required to liquity 
a gas at its critical temperature. 
16. Critical Volume : The volume of 1 mole of gat at Tc, Pc. 
17. Super cooled liquids : The liquids which are cooled to a 
temperature below its freezing point without freezing . 
75 
 
18. Elastic Collision : The collisions in which no loss of K.E. 
only there is transfer of energy. 
19. Vapour pressure : The equilibrium pressure by vapour of 
liquid in a container at given temperature (T) 
20. At higher altitude : The b.p. of water decreases b/c the 
atmospheric pressure is less than one atmosphere. 
21. Surface Tension  (V) : It is force acting per unit length 
perpendicular to the line drawn on the surface : (Nm
-1
) :  It 
decreases with increases in T, it increases with increase in 
external pressure, b/c of it falling drops of liquid are 
spherical, liquid in capillary tube rises.   
22. Viscosity (?) : It is resistance offered to the flow of liquid 
due to friction b/w layer of  fluids . 
dn
dv
A n F . . 
23. Effect of T & P on viscosity  : It decreases with increase in 
T, and increases with increase in P. 
24. Low M.P. & B.P. of molecular liquids is due to low 
magnitude of molecular interaction energy. 
One mark questions 
1. At what condition surface tension vanishes ? 
2. Why Helium is used in balloons in place of hydrogen? 
3. At what temperature below which a gas does not obey ideal 
gas law? 
4. At what temperature the volume of a gas is supposed to be 
zero? 
5. What is the molar volume at 0
o
C and 1 bar pressure? 
76 
 
6. Name the temperature above which a gas cannot be 
liquefied  by any amount of pressure. 
7. What is the effect of increase of temperature on surface 
tension and viscosity in a liquid? 
8. How is the partial pressure of a gas in a mixture is related to 
the total pressure of the gaseous mixture? 
9. Why vegetables are cooked with difficulty at hill station. 
10. What is the value of Z (compressibility factor) for an Ideal 
gas? 
Answers to One mark questions 
Ans 1 At critical temperature, meniscus b/w liquid and vapours 
disappears. 
Ans 2. He is incombustible , though heavier than H
2 
. 
Ans 3. Below Boyle Temperature. 
Ans 4. At absolute zero (O K) temperature. 
Ans 5. It 22400 ml. 
Ans 6. It is critical temperature (Tc) 
Ans 7. Both decreases with increase in temperature 
Ans 8. P
1
 = X
1
 x P 
(total)
 
Ans 9. At hill station the atmospheric pressure is less and so 
boiling point decreases. 
Ans10. For ideal gas Z=1. 
 
Two Marks Questions 
Q.1 How do you convert pressure in atmosphere in to SI unit. 
Page 5


73 
 
CHAPTER 5 
STATES OF MATTER 
1. Change in state : It is over all effect of Intermolecular 
forces, molecular  Interactional energy & thermal energy: 
2. Measurable properties of gases : P,V, T, n, Viscosity, 
specific heat  are some measurable properties. 
3. Gas Laws : The quantitative relationship b/w any two of 
the variables (V, n, P,T) when other two are constant. 
4. Boyle’s Law : The pressure of fixed msss of gas varies 
inversely with the volume at constant T. P a 1/V(n,T const.) 
P
1
V
1
 = P
2 
V
2
 
5. Charle’s Law : At constant P, the volume of fixed amount 
of gas varies directly with its absolute temperature.  
V a T    or     
2
2
1
1
, tan
T
V
T
V
t cons
T
V
 
6. Gay lussac’s Law : At constant V, The pressure of fixed 
amount of gas varies directly with its absolute temperature. 
P a T     or   
2
2
1
1
,
T
P
T
P
const
T
P
 
7. Ideal gas equation  : The relationship b/w P, V and T by 
Gas Laws  PV= nRT. 
8. Avogadro’s Law : At given T and P, the volume of gas 
varies directly to the amount of gas .   V a n ( P, T constant) 
9. Dalton’s Law of partial persure :  The pressure enerted by a 
mixture of non reacting gases is equal to the sum of their 
partial pressure at constant (V,T) 
74 
 
P (total ) = P1 + P2 + P3 + ………. (T, V, constant) 
10. Kinetic Molecular theory :  
a. Gases consist of large number of identical particles 
(atoms or molecules) that are so small that the actual 
volume of the molecules is negligible in comparison to 
the empty space between them.  
b. There is no force of attraction between the particles of a 
gas at ordinary temperature and pressure  
c. Particles of a gas are always in constant and random 
motion 
d. Pressure is exerted by the gas as a result of collision of 
the particles with the walls of the container 
e. Collisions of gas molecules are perfectly elastic 
f. At any particular time, different particles in the gas have 
different speeds and hence different kinetic energies 
g. Average kinetic energy of the gas molecules is directly 
proportional to the absolute temperature 
11. Real Gases : The gases which deviates from Ideal behavior 
at higher pressure and low temperature b/c of force of 
attraction b/w molecules increases . 
12. Compressibility factor (Z) : It determine extent of devation 
of real gases from Ideal gas behavior : Z = 
. . . T R n
PV
  for ideal 
gas Z=1, for Nonideal gas Z< 1, Z > 1 
13. Vander waal’s Equation : .
2
2
nRT nb V
V
a n
P 
14. Critical Temperature : (Tc) The temperature above which a 
gas cannot be liquefied whatever high pressure may be 
15. Critical Pressure : The minimum pressure required to liquity 
a gas at its critical temperature. 
16. Critical Volume : The volume of 1 mole of gat at Tc, Pc. 
17. Super cooled liquids : The liquids which are cooled to a 
temperature below its freezing point without freezing . 
75 
 
18. Elastic Collision : The collisions in which no loss of K.E. 
only there is transfer of energy. 
19. Vapour pressure : The equilibrium pressure by vapour of 
liquid in a container at given temperature (T) 
20. At higher altitude : The b.p. of water decreases b/c the 
atmospheric pressure is less than one atmosphere. 
21. Surface Tension  (V) : It is force acting per unit length 
perpendicular to the line drawn on the surface : (Nm
-1
) :  It 
decreases with increases in T, it increases with increase in 
external pressure, b/c of it falling drops of liquid are 
spherical, liquid in capillary tube rises.   
22. Viscosity (?) : It is resistance offered to the flow of liquid 
due to friction b/w layer of  fluids . 
dn
dv
A n F . . 
23. Effect of T & P on viscosity  : It decreases with increase in 
T, and increases with increase in P. 
24. Low M.P. & B.P. of molecular liquids is due to low 
magnitude of molecular interaction energy. 
One mark questions 
1. At what condition surface tension vanishes ? 
2. Why Helium is used in balloons in place of hydrogen? 
3. At what temperature below which a gas does not obey ideal 
gas law? 
4. At what temperature the volume of a gas is supposed to be 
zero? 
5. What is the molar volume at 0
o
C and 1 bar pressure? 
76 
 
6. Name the temperature above which a gas cannot be 
liquefied  by any amount of pressure. 
7. What is the effect of increase of temperature on surface 
tension and viscosity in a liquid? 
8. How is the partial pressure of a gas in a mixture is related to 
the total pressure of the gaseous mixture? 
9. Why vegetables are cooked with difficulty at hill station. 
10. What is the value of Z (compressibility factor) for an Ideal 
gas? 
Answers to One mark questions 
Ans 1 At critical temperature, meniscus b/w liquid and vapours 
disappears. 
Ans 2. He is incombustible , though heavier than H
2 
. 
Ans 3. Below Boyle Temperature. 
Ans 4. At absolute zero (O K) temperature. 
Ans 5. It 22400 ml. 
Ans 6. It is critical temperature (Tc) 
Ans 7. Both decreases with increase in temperature 
Ans 8. P
1
 = X
1
 x P 
(total)
 
Ans 9. At hill station the atmospheric pressure is less and so 
boiling point decreases. 
Ans10. For ideal gas Z=1. 
 
Two Marks Questions 
Q.1 How do you convert pressure in atmosphere in to SI unit. 
77 
 
Q.2 What type graph will you get when PV is plotted against P 
at constant temperature. 
Q.3 What would have happened to the gas if the molecular 
collisions were not elastic? 
Q.4 At a particular temperature, why vapour pressure of acetone 
is less than of ether? 
Q.5 Why liquids diffuse slowly as compared to gases? 
Q.6 What would be the SI unit for quantity ?
. .
2 2
n
T V P
 
Q.7 In terms of Charle’s law explain why -273
o
 C is the lowest 
temperature? 
Q.8 For real gases the relation b/w P,V,T is given by vander 
Waal’s equation, write it for n moles? 
Q.9 What correction is applied to obtain pressure of dry gas 
with the total pressure & aqueous tension? 
Q.10 Name two phenomena  that can be explained on  the basis 
of surface  tension. 
Answers to two marks questions 
Ans 1. 1atm = 101325 Pa or Nm
-2
, 1 bar = 10
5
  Pa. 
Ans 2 .A straight line parallel to pressure axis. 
Ans 3. On every collision there is loss of energy, so molecules 
would have slowed down & settled down in vessel and 
pressure reduce to O. 
Ans 4. b/c molecular force of attraction in acetone is stronger 
than those present in ether.