แรงกระทำระหว่างโมเลกุล (intermolecular forces)

แรงกระทำ��ระหว่��งโมเลก�ล (Intermolecular Forces)

เนื้��อห�ทำ��จะเร�ยนื้1 Intermolecular Forces and some Properties of Liquids

2 Vaporization of Liquids: Vapor Pressure

3 Some Properties of Solids

4 Phase Diagrams

5 Van der Waals Forces

6 Hydrogen Bonding

7 Network Covalent Solids and Ionic Solids

Cohesive Forces Intermolecular forces between like molecules.

Adhesive Forces Intermolecular forces between unlike molecules.

Surface Tension Energy or work required to increase the surface area

of a liquid. Viscosity

A liquids resistance to flow

Intermolecular Forces and Some Properties of Liquids

Intermolecular Forces

Intermolecular Forces

Vaporization of Liquids:Vapor Pressure

ΔHvap = Hvapor – Hliquid = - ΔHcondensation

Boiling Point

Mercury manometer

Vapor pressure of liquid

Pvap independent

of Vliq

Pvap independent

of Vgas

Pvap dependent on

T

Vapor Pressure and Boiling Point

Vapor Boils at Low Pressure

The Critical Point

•ความหนาแน�นของของเหลวลดลงแต่�ของไอจะเพิ่��มข��นและต่�อมาจะม�ค�าเท่�ากั�น•แรงต่�งผิ�วของของเหลวจะเข�าใกัล�ศู!นย์# ชั้� �นของของเหลวและไอจะกัลาย์เป็'นหน��งเด�ย์ว

ไม�เห(นความแต่กัต่�าง

ตั�ว่อย��งก�รใช้�ข้�อม ลคว่�มดั�นื้ไอ

จากัป็ฏิ�กั�ร�ย์าเคม�ชั้น�ดหน��งได�ผิล�ต่ภั�ณฑ์#เป็'นน-�ามวล 0.132 g ท่��อ.ณหภั!ม� 50.0 oC ในภัาชั้นะป็/ดป็ร�มาต่ร 525 mL จงท่-านาย์ว�าน-�าน��จะอย์!�ในสถานะ

(a) liquid only(b) vapor only(c) liquid-vapor equilibrium

Clausius-Clapeyron Equation

ln = - ( - ) P2

P1

1T2

1T1

ΔHvap

R

ln P = -A ( ) + B1T

A = ΔHvap

R

Some Properties of Solids

Freezing Point

ΔHfus(H2O) = +6.01 kJ/mol

Melting Point

Sublimation

ΔHsub = ΔHfus + ΔHvap

= -ΔHdeposition

Phase Diagrams

Iodine

Phase Diagrams

Carbon dioxide

Supercritical Fluids

Decaffeination with Supercritical CO2

Water

Prentice-Hall © 2007General Chemistry: Chapter 12Slide 24 of 54

Interpreting a Phase Diagram

Van der Waals Forces

Instantaneous dipoles. Electrons move in an orbital to cause a polarization.

Induced dipoles. Electrons move in response to an outside force.

Dispersion or London forces. Instantaneous dipole – induced dipole attraction. Related to polarizability.

Phenomenon of Induction

Instantaneous and Induced Dipoles

< 10 kJ/mol

Dipole Dipole Interactions

5 to 20 kJ/mol

Prentice-Hall © 2007General Chemistry: Chapter 12Slide 29 of 54

Electrostatic Potential Maps

คว่�มสั�มพั�นื้ธ์'ระหว่��งแรงกระทำ��ระหว่��งโมเลก�ลก�บสัมบ�ตั)ข้องสั�รประกอบ

เร�ย์งล-าด�บจ.ดเด3อดของสารต่�อไป็น��: CCl4, Cl2, ClNO, N2. จ.ดเด3อดท่��พิ่บ

จร�ง

CCl4 =

349.9 K

ClNO = 266.7 K

Cl2 = 239.1

K

N2 = 77.3 K

Hydrogen Bonding

15 to 40 kJ/mol

Hydrogen Bonding

Hydrogen Bonding in HF(g)

Hydrogen Bonding in Water

around a molecule in the solid in the liquid

Other examples of H-Bonds

DNA Double Helix

The Polymerase Chain Reaction (PCR)

Network Covalent Solids and Ionic Solids

Other Carbon Allotropes

Interionic Forces

Energy Changes in the Formation of Ionic Crystals

Ion-dipole Interactions

cation- Interactions

anion- Interactions

- Interactions

Hydrophobic Effects

Focus On Liquid Crystals

Liquid Crystal Thermometers

End of Chapter Questions

If I had the answer, what would I have used to get it.

You can think about problems in reverse to help sort out a strategy.

a

b

c