![Page 1: Chem-To-Go Lesson 37 Unit 9 COLLIGATIVE PROPERTIES](https://reader038.vdocuments.us/reader038/viewer/2022100505/5a4d1b7a7f8b9ab0599b8a9b/html5/thumbnails/1.jpg)
Chem-To-Go Lesson 37Unit 9
COLLIGATIVE PROPERTIES
![Page 2: Chem-To-Go Lesson 37 Unit 9 COLLIGATIVE PROPERTIES](https://reader038.vdocuments.us/reader038/viewer/2022100505/5a4d1b7a7f8b9ab0599b8a9b/html5/thumbnails/2.jpg)
COLLIGATIVE PROPERTIES
DEFINITION: a physical property of a solution that differs from the physical property of the solvent due to the presence of the solute particles; the number of solute particles determines the severity of the property’s change
BOILING POINT ELEVATION
The boiling point of a solution will be higher than the normal boiling point of the solvent.• EXAMPLE: Salt water boils
at a higher temperature than pure water.
FREEZING POINT DEPRESSION
The freezing point of a solution will be lower than the normal freezing point of the solvent.• EXAMPLE: Salt water
freezes at a lower temperature than pure water.
![Page 3: Chem-To-Go Lesson 37 Unit 9 COLLIGATIVE PROPERTIES](https://reader038.vdocuments.us/reader038/viewer/2022100505/5a4d1b7a7f8b9ab0599b8a9b/html5/thumbnails/3.jpg)
IONIC SOLUTESIonic solutes
dissociate as they dissolve creating MORE solute particles.
COVALENT SOLUTES
Covalent solutes do not dissociate as they dissolve.
NUMBER OF SOLUTE PARTICLES
![Page 4: Chem-To-Go Lesson 37 Unit 9 COLLIGATIVE PROPERTIES](https://reader038.vdocuments.us/reader038/viewer/2022100505/5a4d1b7a7f8b9ab0599b8a9b/html5/thumbnails/4.jpg)
∆Tf = Kf m i∆Tf = change in
freezing pt.K f = freezing point
constant for the solvent (will be given)
m = molalityi = number of ions
present in solute (USE ONLY WITH IONIC SOLUTES)
FREEZING POINT DEPRESSION
Kf of water = 1.86°C/m
What is the new freezing point when 15.0g NaCl is dissolved into 200 mL of
water?
![Page 5: Chem-To-Go Lesson 37 Unit 9 COLLIGATIVE PROPERTIES](https://reader038.vdocuments.us/reader038/viewer/2022100505/5a4d1b7a7f8b9ab0599b8a9b/html5/thumbnails/5.jpg)
∆Tb = Kb m i∆Tb = change in
boiling pt.Kb = boiling point
constant for the solvent (will be given)
m = molalityi = number of ions
present in solute (USE ONLY WITH IONIC SOLUTES)
BOILING POINT ELEVATION
Kb of water = 0.52°C/m
What is the new boiling point when 15.0g NaCl is dissolved
into 200 mL of water?
![Page 6: Chem-To-Go Lesson 37 Unit 9 COLLIGATIVE PROPERTIES](https://reader038.vdocuments.us/reader038/viewer/2022100505/5a4d1b7a7f8b9ab0599b8a9b/html5/thumbnails/6.jpg)
CIVIL ENGINEERING APPLICATION: How many grams of NaCl would need to be added to the water to change the freezing temperature of 200 mL to -8°C?
MORE ADVANCED EXAMPLE