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CHEMISTRY
INVESTIGATORY
PROJECT
SESSION-2015-16
TOPIC: - COLLIGATIVE PROPERTY
MADE BY: - CHINMAYA JAGADEV
PATTANAYAK
2
GUIDED BY: -MR. S.K.BAGH (PGT Chemistry)
3
Certificate
This is to certify that Master Chinmaya
Jagadev Pattanayak bearing Roll No. __________ of
class-XII(science....
4
Signatureofstudent:
SignatureofGuide:- SignatureofPrincipal:
MR. S.K. BAGH MR. N.C. KAR
5
ACKNOWLEDGEMENT
I wish to express my deep sense of gratitude to them
whose encouragement and cooperation has been a
sour...
6
7
CONTENTS:-
What is colligative property?
Types of colligative property
Lowering Vapour Pressure (∆P) of
solutions.
Boili...
8
WHAT IS COLLIGATIVE PROPERTY?
In chemistry, colligative properties are properties
of solutions that depend upon the rati...
9
4. Osmosis.
10
1.Lowering Vapour Pressure (∆P) of solutions: Roult’s
law:-
When a non-volatile solute is added to a solvent, the
vapou...
11
Vapour pressure of the solvent in solution = P1
P1 = x1P1°
ΔP1 = P1° - P1
= P1° - x1P1°
= P1° (1 - x1)
In a binary solu...
12
equal to the sum of the mole fractions of all the
non-volatile solutes.
If n1 and n2 are respectively the number of mol...
13
2. Boiling point elevation (ΔTB ):-
The exact relation between the boiling point of the solution
and the mole fraction ...
14
At any temperature, the vapour pressure of a solution
containing a non-volatile solute is less than that of the pure
so...
15
Molal elevation constant is defined as the elevation in the
boiling point when 1mole of a solute is dissolved in
1kilog...
16
When a non-volatile solute is added to a solvent, the
freezing point of the solution gets lowered.
According to Roult’s...
17
M1= Molar mass of the solvent
Tf = Freezing point of the pure solvent
ΔfusH = Enthalpy for the fusion of the solvent
If...
18
Vegetable membranes, membranes found under the shell
of an egg are examples of natural membranes and
cellophane is an e...
19
Thus, osmotic pressure π of a solution is defined as the
excess pressure that must be applied to a solution to
prevent ...
20
π = W2RT / M2V
M2 = W2RT / πV
This is widely used to determine the molar masses of
polymers and macromolecules, especia...
21
BIBLIOGRAPHY:-
1. www.google.com
2. www.slideshare.com
3. www.icbse.com
4. www.wikipedia.com
5. www.yahoo.com
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colligative property ,made by-chinmay jagadev pattanayak

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What is colligative property?
Types of colligative property
Lowering Vapour Pressure (∆P) of solutions.
Boiling point elevation.
Freezing point depression
Osmotic pressure of the solution

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colligative property ,made by-chinmay jagadev pattanayak

  1. 1. 1 CHEMISTRY INVESTIGATORY PROJECT SESSION-2015-16 TOPIC: - COLLIGATIVE PROPERTY MADE BY: - CHINMAYA JAGADEV PATTANAYAK
  2. 2. 2 GUIDED BY: -MR. S.K.BAGH (PGT Chemistry)
  3. 3. 3 Certificate This is to certify that Master Chinmaya Jagadev Pattanayak bearing Roll No. __________ of class-XII(science.) JAWAHAR NAVODAYA VIDYALAYA, Sarang, Dhenkanal (ODISHA) has successfully completed the project on the topic “COLLIGATIVE PROPERTY” under the guidance of Mr.S.K. Bagh (P.G.T.Chemistry). This project can be approved as a part of C.B.S.E in the session 2015-2016.
  4. 4. 4 Signatureofstudent: SignatureofGuide:- SignatureofPrincipal: MR. S.K. BAGH MR. N.C. KAR
  5. 5. 5 ACKNOWLEDGEMENT I wish to express my deep sense of gratitude to them whose encouragement and cooperation has been a source of inspiration. It’s an honor to thank our principal Mr.N.C.Kar, Jawahar Navodaya Vidyalaya, Sarang,Dhenkanal for providing me the opportunity to makethis project andlearn through it. Iwould like to thank Mr.S.K. Bagh (PGT Chemistry) for providing us the right direction and for his cooperationandhelpin successful completionof our project. I amindebtedtobothofthemfortheirhelp. .
  6. 6. 6
  7. 7. 7 CONTENTS:- What is colligative property? Types of colligative property Lowering Vapour Pressure (∆P) of solutions. Boiling point elevation. Freezing point depression Osmotic pressure of the solution.
  8. 8. 8 WHAT IS COLLIGATIVE PROPERTY? In chemistry, colligative properties are properties of solutions that depend upon the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the type of chemical species present. The number ratio can be related to the various units for concentration of solutions. The independence of the nature of solute particles is exact for ideal solutions, and approximate for dilute real solutions. Here we consider only those properties which result because of the dissolution of nonvolatile solute in a volatile liquid solvent. They are independent of the nature of the solute because they are due essentially to the dilution of the solvent by the solute. The word colligative is derived from the Latin colligatus meaning bound together. TYPES OF COLLIGATIVE PROPERTY:- 1. Lowering Vapour pressure of solution: Roult’s law. 2. Elevation in boiling point (ΔTB ). 3. Depression in freezing point (ΔTf ).
  9. 9. 9 4. Osmosis.
  10. 10. 10 1.Lowering Vapour Pressure (∆P) of solutions: Roult’s law:- When a non-volatile solute is added to a solvent, the vapour pressure of the solution decreases. According to Roult’s Law, the vapour pressure of a solvent (P1) in a solution containing a non-volatile solute is given by According to Raoult's Law, Vapour pressure of the pure solvent = P1°
  11. 11. 11 Vapour pressure of the solvent in solution = P1 P1 = x1P1° ΔP1 = P1° - P1 = P1° - x1P1° = P1° (1 - x1) In a binary solution, 1 - x1 = x2 ΔP1 = P1° x2 ΔP1/P1° = (P1° - P1)/P1° = x2 The lowering of vapour pressure relative to the vapour pressure of pure solvent is called relative lowering of vapour pressure. ΔP1/P1° → Relative lowering of Vapour pressure Thus, the relative lowering in vapour pressure depends only on the concentration of solute particles and is independent of their identity. If the solution contains more than one non-volatile solute, then the relative lowering in vapour pressure of a solvent is
  12. 12. 12 equal to the sum of the mole fractions of all the non-volatile solutes. If n1 and n2 are respectively the number of moles of the solvent and solute in a binary solution, then the relative lowering in the vapour pressure of the solvent, (P1° - P1)/P1° = x1 + x2 + x3 + ... + xn if n1 and n2 are the number of moles of the solvent and solute, (P1° - P1)/P1° = n2/(n1+n2) For dilute solutions n2 << n1 (P1° - P1)/P1° = n2/n1 n1 = W1/M1 , n2 = W2/M2 (P1° - P1)/P1° = (W2xM1)/(W1xM2) W1 = Mass of solvent W2 = Mass of solute M1 = Molar mass of solvent M2 = Molar mass of solute
  13. 13. 13 2. Boiling point elevation (ΔTB ):- The exact relation between the boiling point of the solution and the mole fraction of the solvent is rather complicated, but for dilute solutions the elevation of the boiling point is directly proportional to the molal concentration of the solute: OR ΔTb = Kb.Cm Kb = Ebullioscopy constant, which is 0.512°C kg/mol for the boiling point of water. The vapour pressure of a liquid increases with an increase in temperature. When vapour pressure of the liquid becomes equal to the atmospheric pressure (or) external pressure, then liquid starts boiling. The temperature at which the vapour pressure of the liquid is equal to the external pressure is known as its boiling point.
  14. 14. 14 At any temperature, the vapour pressure of a solution containing a non-volatile solute is less than that of the pure solvent. The temperatures at which the vapour pressure of the solvent and the solution become equal to the atmospheric pressure are Tb0 and Tb. Tb-Tb0 =∆Tb Thus, it can be seen that the boiling point of a solution is greater than the boiling point of the pure solvent. The boiling point of a solvent changes as the concentration of the solute in the solution changes, but it does not depend on the identity of the solute particles. The elevation of the boiling point depends upon the concentration of the solute in the solution and is directly proportional to molality (m) of the solute in the solution. ΔTb = Tb - Tb° Tb > Tb° ΔTb ∝ Concentration of solute ΔTb ∝ m (Molarity) ΔTb = Kb m Kb = Boiling point elevation constant or molal elevation constant or ebullioscopic constant
  15. 15. 15 Molal elevation constant is defined as the elevation in the boiling point when 1mole of a solute is dissolved in 1kilogram of a solvent. If w2 grams of a solute with M2 molar mass is dissolved in w1gram of a solvent, then molality (m) of the solution is, m = (W2x1000)/(W1xM2) ΔTb = Kb (W2x1000)/(W1xM2) 3. Freezing Point Depression (ΔTf ):- The freezing point of a substance is defined as the temperature at which its solid phase is in dynamic equilibrium with its liquid phase. At the freezing point, the vapour pressure of the substance in its liquid phase is the same as the vapour pressure of the substance in its solid phase.
  16. 16. 16 When a non-volatile solute is added to a solvent, the freezing point of the solution gets lowered. According to Roult’s law, the vapour pressure of a solution containing a non-volatile solute is lower than that of the pure solvent. Thus freezing point of a solvent decreases when a non-volatile solute is added to it. The depression in freezing point depends upon the concentration of the solution. For dilute solutions, depression in the freezing point is directly proportional to molality (m). Thus, ∆Tf =Kf m Where Kf =freezing point depression constant (or) molal depression constant (or) cryoscopic constant. Molal depression constant Kf can be defined as the depression in freezing point when 1mole of solute dissolved in 1kg of solvent. The unit for Kf is kelvin kilogram /mole. As Kf depends upon the nature of the solvent, its value is different for different solvents. The values of Kf can be calculated from this expression Kf = (R x M1 x Tf 2 )/(1000 x ΔfusH) R = Gas constant
  17. 17. 17 M1= Molar mass of the solvent Tf = Freezing point of the pure solvent ΔfusH = Enthalpy for the fusion of the solvent If w2 grams of a solute with molar mass M2 is dissolved in w1 grams of a solvent, then molality m of the solution is given by W2 multiplied by 1,000 divided by w1 multiplied by M2 Substituting this value of molality in the freezing point depression equation, we get depression in freezing point Molarity , m = (W2 x 1000)/(W1xM2) ΔTf = Kf m ΔTf = (Kf x W2 x 1000)/(W1xM2) M2 = = (Kf x W2 x 1000)/(W1xΔTf) Thus, the molar mass of a non-ionic solute can be calculated by using the depression in freezing point. 4. Osmosis:- Membranes which allows only solvent particles but not solute particles of solution is called semi-permeable membranes (or) SPM. These membranes can be of natural origin (or) synthetic origin.
  18. 18. 18 Vegetable membranes, membranes found under the shell of an egg are examples of natural membranes and cellophane is an example of synthetic membrane. Thus 'Osmosis' can be defined as the spontaneous flow of solvent through a semi-permeable membrane from a pure solvent to a solution or from a dilute solution to a concentrated solution. It is important to note that osmosis drives solvent molecules through a semi-permeable membrane from low solute concentrations to high solute concentrations. Osmosis ends when the solute concentration becomes equal on either side of the membrane and equilibrium is attained. The flow of solvent molecules from low concentration to high concentration can be stopped by applying some extra pressure on the high concentration side. The minimum pressure required to do so is known as the osmotic pressure of the solution.
  19. 19. 19 Thus, osmotic pressure π of a solution is defined as the excess pressure that must be applied to a solution to prevent osmosis from taking place. Osmotic pressure does not depend on the identity of the solute, but on its concentration. Osmotic pressure for dilute solutions is proportional to molarity of the solution at a given temperature(T). π ∝ C (at given T) π = C R T R = Gas constant C = n2/V π = n2RT / V If W2 grams of solute of molar mass M2 is present in the solution, n2 = W2/M2
  20. 20. 20 π = W2RT / M2V M2 = W2RT / πV This is widely used to determine the molar masses of polymers and macromolecules, especially biomolecules, as they are generally unstable at higher temperatures and decompose before their boiling point is reached. If the solutions have the same concentrations (C1 = C2), then π1= π2.
  21. 21. 21 BIBLIOGRAPHY:- 1. www.google.com 2. www.slideshare.com 3. www.icbse.com 4. www.wikipedia.com 5. www.yahoo.com

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