Unit # 4 Colligative Properties.. Colligative Properties - Properties that depend on the concentration of solute molecules or ions in solution, but do.

Slides:



Advertisements
Similar presentations
CALCULATIONS INVOLVING COLLIGATIVE PROPERTIES
Advertisements

Colligative Properties
Chapter 12 Solutions.
Chapter 13- Unit 2 Colligative Properties - are properties of solutions that depend on the number of molecules in a given volume of solvent and not on.
Colligative Properties of Solutions
Physical Properties of Solutions Chapter 12 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Molecular Mass by Freezing Point Depression Background Vapor Pressure  The melting and freezing points for a substance are determined by the vapor pressure.
Colligative Properties
Colligative Properties (solutions)
Calculations Involving Colligative Properties Review Molarity (M) = moles of solute liter of solution Dilutions: M 1 x V 1 = M 2 x V 2 Percent by volume.
Calculations Involving Colligative Properties. Introduction We now understand colligative properties. To use this knowledge, we need to be able to predict.
Physical Properties of Solutions
Solutions Chapter 16 Copyright © The McGraw-Hill Companies, Inc.
1 © 2009 Brooks/Cole - Cengage Solutions Chapter 14 Why does a raw egg swell or shrink when placed in different solutions? PLAY MOVIE.
SOLUTIONS SUROVIEC SPRING 2014 Chapter 12. I. Types of Solution Most chemical reaction take place between ions/molecules dissolved in water or a solvent.
Chapter 13.  A solution forms when one substance disperses uniformly throughout another.  The reason substances dissolve is due to intermolecular forces.
Colligative Properties of Solutions. How do you get from this…
Calculations Involving Colligative Properties Prentice-Hall Chapter 16.4 Dr. Yager.
Concentration Units Molarity Molality Mole Fraction Weight Percent ppm ppb.
Properties of Solutions Chapter 18 Lesson 3. Solution Composition Mass percentage (weight percentage): mass percentage of the component = X 100% mass.
CH 11: Properties of Solutions
Colligative Properties. Properties that depend upon the concentration of solute particles are called colligative properties. Generally these properties.
Prentice Hall ©2004 CHAPTER 11 SOLUTIONS AND THEIR PROPERTIES Chapter 11Slide 1.
Chapter 12 Solutions. From Chapter 1: Classification of matter Matter Homogeneous (visibly indistinguishable) Heterogeneous (visibly distinguishable)
White Board Review Practicing with Colligative Properties Boiling Point Elevation Freezing Point Depression Osmotic Pressure.
Change in Freezing Point Common Applications of Freezing Point Depression Propylene glycol Ethylene glycol – deadly to small animals.
Colligative Properties. Definition Properties that depend on the concentration of a solution no matter what the solute’s identity is.
1 Colligative Properties of Solutions Colligative properties are properties that depend only on the number of solute particles in solution and not on the.
Colligative Properties OF SOLUTIONS. Colligative Property A property that depends only on the number of particles, and not on their identity 3 Colligative.
III. Colligative Properties (p )
II III I IV. Colligative Properties of Solutions (p. 498 – 504) Ch. 14 – Mixtures & Solutions.
Freezing Point Depression When the rate of freezing is the same as the rate of melting, the amount of ice and the amount of water won't change. The.
II III I C. Johannesson III. Colligative Properties (p ) Ch. 13 & 14 - Solutions.
Colligative Properties. _______________ – physical properties of solutions that are affected only by the number of particles NOT the identity of the solute.
Calculations Involving Colligative Properties Freezing Point Depression and Boiling Point Elevation Calculations.
CHP 12 solutions Concentration There are numerous ways to measure concentration –(amount of solute/amount of solvent or soln) Molarity, M Molality, m.
Colligative Properties of solutions A colligative property is that which depends on the relative number of solute and solvent molecules.
Solutions Homogeneous Mixture of 2 or more Substances.
Solutions --don’t worry—we’ll have problems to go with them.
Chapter Colligative Properties: Property of the solvent that depends on the number, not the identity, of the solute particles. 2 assumptions: no.
COLLIGATIVE PROPERTIES OF SOLUTIONS. Colligative Properties  A property that depends only upon the number of solute particles, and not upon their identity.
1 Physical Properties of Solutions For Exam 3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
SOLUTIONS SUROVIEC SPRING 2015 Chapter 12. I. Types of Solution Most chemical reaction take place between ions/molecules dissolved in water or a solvent.
1 © 2006 Brooks/Cole - Thomson Chemistry and Chemical Reactivity 6th Edition John C. Kotz Paul M. Treichel Gabriela C. Weaver CHAPTER 14 Solutions and.
Unit # 4 Colligative Properties.. Colligative Properties - Properties that depend on the concentration of solute molecules or ions in solution, but do.
Chapter 11 Properties of Solutions. Copyright © Cengage Learning. All rights reserved 2 Solution – a homogeneous mixture. Solute – substance being dissolved.
Physical Properties of Solutions Chapter 12 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
CHAPTER 12: Concentration Terms for Solutions Concentration = Amount solute/amount solvent Some Concentration Terms are Temperature Sensitive.
Notes 13-3 Obj 13.4, © 2009, Prentice- Hall, Inc. A.) Mass Percentage Mass % of A = mass of A in solution total mass of solution  Ways.
11.4 Colligative Properties
Colligative Properties
V. Colligative Properties
Colligative Properties
13.5 Colligative properties
Objectives/Goals for Today
Solutions Chapter 10.
III. Colligative Properties
Sample Exercise 13.1 Predicting Solubility Patterns
Colligative Properties of Solutions
Chapter 13-2 Colligative Properties of Solutions
8.3 Colligative Properties Objective S3
Calculations Involving Colligative Properties
Physical Properties of Solutions
Lesson 6.1: Solutions and Concentration
Colligative Properties of Solutions
III. Colligative Properties (p )
Section 3 – Colligative Properties of Solutions
Vapor-Pressure Lowering
Colligative Properties of Solutions
Presentation transcript:

Unit # 4 Colligative Properties.

Colligative Properties - Properties that depend on the concentration of solute molecules or ions in solution, but do not depend on the chemical identity of the solute. (For example, addition of Ethylene glycol or Urea to water will have the same effect.)

Examples of Colligative Properties: 3.Vapor pressure lowering 1.Boiling point elevation 2.Freezing point depression

The above colligative properties depend on the mole fraction of the solvent. Mole fraction - The mole fraction of substance “A” is represented as X A X A = # of moles of “A” Total moles of solution (solute + solvent)

Example #1: A solution is 1 mol Ethylene glycol and 9 mol water. Calculate the mole fraction of both the solute and the solvent.

X Ethylene glycol = 1 mol Ethylene glycol 10 mol solution x 100 X Ethylene glycol = 10 %

X Water = 9 mol water 10 mol solution x 100 X Water = 90 %

Example #2: What are the mole fractions of glucose and water in a solution containing 5.67g of glucose dissolved in 25.2g of water ?

Clues: 1.Determine the chart mass of the solute and the solvent. 2.Determine the number of moles of the solute and solvent 3.Use the mole fraction formula to solve.

Glucose = C 6 H 12 O 6 = g/mol Use “DIMO” to calculate moles. 5.67g glucose = mol glucose

Water = H 2 O = g/mol Use “DIMO” to calculate moles. 25.2g water =1.40 mol water

Mole fraction glucose mol glucose mol solution = x 100 = 2.20 % Mole fraction water 1.40 mol water mol solution = x 100 = 97.8 %

Example #3: A bleaching solution contains Sodium hypochlorite, NaClO, dissolved in water. The bleach is 0.750m NaClO. What is the mole fraction of Sodium hypochlorite ?

Clues: 1.Recall the definition of molality. 2.Convert Kg of solvent to moles 3.Use the mole fraction formula to solve

0.750m = mol NaClO 1 Kg solvent 1 Kg solvent (water) = 55.5 mol water X NaClO = mol NaClO mol solution = %

Example #4: Vinegar is 0.763M Acetic acid, CH 3 COOH. The density is g/mL. What is the mole fraction of the acetic acid ?

Vapor pressure lowering - Vapor pressure lowering of a solvent is equal to the vapor pressure of the pure solvent minus the vapor pressure of the solution. There are three formulas associated with Vapor Pressure Lowering.

1.  P lowering = Vapor pressure solvent - VP solution 2.  P lowering = P Å x X B P Å = vapor pressure of pure solvent X B = mole fraction of solute 3.  P lowering = P Å - P A P A = partial pressure of solvent

V.P. lowering example #1: V.P. water = mmHg V.P m antifreeze sol’n = mmHg V.P. lowering = 0.18 mmHg Lowering vapor pressure, increases boiling point.

V.P. lowering example #2: How much will the vapor pressure of water drop when 5.67g of glucose are dissolved in 25.2g of water at 25  C and what will the new vapor pressure be ? V.P. water 25  = 23.8 mmHg Clue: Use:  P lowering = P Å x X B

 P lowering = P Å x X B 5.67g glucose = mol 25.2g water = 1.40 mol Total mol = mol Mol fraction glucose = = 23.8 mmHg x = mmHg

New V.P. = V.P. pure solvent - drop in V.P. = 23.8 mmHg mmHg = 23.3 mmHg

V.P. lowering example #3: Calculate the vapor pressure at 35  C of a solution made by dissolving 20.2g of sucrose, C 12 H 22 O 11, in 60.5g of water ? V.P. water 35  C = 42.2 mmHg

V.P. lowering example #4: Naphthalene, C 10 H 8, is used to make mothballs. Suppose 0.515g of Naphthalene are dissolved into 60.8g of chloroform, CHCl 3 ; calculate the new vapor pressure of the solvent. V.P. chloroform 20  C = 156 mmHg

Boiling point elevation -  T b equals the boiling point of the solution minus the boiling point of the pure solvent.  T b = i K b C m where i = The number of ions if dissolved in water. K b = boiling point elevation constant (depends on the solvent) C m = molal concentration (m = # mol solute/Kg solvent)

What is the “Normal Boiling Point” of a substance? The temperature at which the vapor pressure equals 1 atmosphere. Therefore if: Vapor Pressure increases, Boiling Point decreases. Vapor Pressure decreases, Boiling Point increases.

Freezing point elevation -  T f equals the freezing point of the pure solvent minus the freezing point of the solution.  T f = K f C m where K f = freezing point depression constant (depends on the solvent) C m = molal concentration (m = # mol solute/Kg solvent)