1. Chapter 5. Solutions of Nonelectrolytes

2. Contents Introductions Concentration expressions Equivalent weights
Ideal solution & Real solution
Colligative properties

3. Solution Composition Classification Solvent Solute
True solution ex) sucrose soln., air
Coarse dispersion ex) spray, blood
Colloidal dispersion ex) acacia soln., milk

4. Properties of Solutions
Colligative properties
vapor pressure lowering,
freezing point depression
Additive properties
molecular weight
Constitutive properties
refraction of light, electric properties

5. Concentration Expressions
Symbol
Molarity
Normality
Molality
Mole fration
Mole percent
Percent
M, c N m
X, N
% w/w, v/v, w/v
Characteristics
Dependent on temp.
Independent on temp.

6. Equivalent Weights Equivalent weight is ….
The quantities of atom or molecule combining with g of hydrogen
Equivalent weight
= atomic weight / valence

7. Ideal Solution
NaCl
0.01mole
“분자간의 인력이 균일”
1 L

8. Escaping Tendency
Temperature, Concentration, Pressure…..

9. Vapor Pressure
Equilibrium
vapor pressure

10. Raoult’s Law
PA= P’A * XA
PB= P’B * XB
P= PA + PB

11. Real Solution
Adhesion
Cohesion
>
<

12. Negative Deviation > Ex) chloroform + acetone dilution effect
attraction
Van der Waals force

13. Positive Deviation < Psolvent = P’solvent * Xsolvent
Ex) benzene + ethanol
escaping tendency의 증가
부분 증기압 증가
Psolvent = P’solvent * Xsolvent

14. Henry’s Law
Psolute = Ksolute * Xsolute

15. Distillation of Binary Mixturev2
Vapor d v1
Liquid b
Temperature
A e f a c B
Mole fraction

16. Azoetrope A mixture of constant composition and constant boiling point
ex) HCl in water
20.22% (w/w)
bp : ℃

17. Vapor Pressure Psolvent = P’solvent * Xsolvent P / P’solvent = Xsolute
측정: manometer,
osmometer,
isopiestic method,
thermoelectric
method

18. Boiling Point
Tb = K * X2
= Kb * m
Cottrell boiling
point apparatus

19. Freezing Point
Tf = Kf * m
Beckmann method
Equilibrium method

20. Osmotic Pressure
Osmosis
Osmosis vs VP depression
Osmometer

21. π= R T * m Van’t Hoff’s Law πV = n R T π : osmotic pressure in atm
V : volume of solution in liter
n : number of moles of solute
R : (liter*atm) / (mole*deg)
T : absolute temperature
π= R T * m
Morse Equation
m: Molal conc.

22. Molecular weight determination
1) Vapor pressure lowering 이용
P / P’ = X2 = n2 / (n1 + n2)
W2 / M2
W1 / M1
W2*M1*P’
W1* P =
M2 =

23. Molecular weight determination
2) Boiling point elevation
Freezing point lowering
Tb = Kb * m Tf = Kf * m
1000 * W2
W1 * M2
Kb* 1000 * W Kf* 1000 * W2
W1* P W1* P
m =
M2 = 이용 =

24. Molecular weight determination
3) Osmotic pressure 이용
π = n * R * T / V
n = W2 / M2
W2 * R * T
π * V
M2 =