จิรัฏฐ แสนทนit.geol.science.cmu.ac.th/~ssaenton/205237/All_Lectures.pdf · Lecture 1 - Introduction 5 Textbooks {Krauskopf, K.B., and D.K. Bird. 1995. Introduction

$Page 1: จิรัฏฐ แสนทนit.geol.science.cmu.ac.th/~ssaenton/205237/All_Lectures.pdf · Lecture 1 - Introduction 5 Textbooks {Krauskopf, K.B., and D.K. Bird. 1995. Introduction$
Lecture 1 - Introduction 1

GEOL 237GEOL 237Principles of Chemical GeologyPrinciples of Chemical Geology

Dr. Dr. SchradhSchradh SaentonSaenton ((จรฏฐ แสนทน))

Department of Geological Sciences

Chiang Mai University, Chiang Mai, Thailand


Course Objectives

To provide basic principles of geochemistry in the areas of crystal chemistry, chemical equilibria, equilibrium thermodynamics, phase rule and phase diagrams, distribution and behaviors of elements in different geologic environments.

To provide basic background for the courses of Igneous and Metamorphic Petrology (205344) and Applied Geochemistry (205481).


Contact Information

Dr. Schradh SaentonOffice: GB107‐3

Phone: 0‐5394‐3417 ext. 1073

Email: [email protected]

Course Webpage

http://it.geol.science.cmu.ac.th/~ssaenton/205237/index.php


Course Assessment

50% which is divided to

10% ¤aæ¹¹e¡çº40% Êoº¡ÅÒ§ÀÒ¤

Homework will be collected but not graded.

50%

For more detail, ask Dr. Burapa.

1st Half 2nd Half

¹a¡È ¡ÉÒµ �o§e¢ �ÒeÃÕÂ¹äÁ�¹�oÂ¡Ç �Ò 80%

¨§ää �Ã aºo¹uÒµãË�e¢ �ÒË�o§Êoº


Textbooks

Krauskopf, K.B., and D.K. Bird. 1995. Introduction to Geochemistry, 3rd Edition. McGraw‐Hill, Inc. Singapore. 647pp.

Klein, C., and Hurlbut, C.S., Jr., 1999, Manual of Mineralogy, John Wiley & Sons, New York, 681 p.

Copy of the textbook (Copy of the textbook (xeroxxerox) will be available in ) will be available in course webpage.course webpage.


TOPICS (June 1 – July 27)

Crystal Chemistry

Mineral Chemistry

Thermodynamics

Aqueous Chemistry (pH, Acid‐Base, Redox, etc.)

Weathering & Soils

Diagenesis

Distribution of Elements in Secondary Environment


Why study geochemistry?

Crystallography

Mineralogy

Petrology

Economic Geology

Sedimentology

etc.

Mineral Exploration

Environmental Geology

Isotope Geochemistry

Hydrogeology

etc.

BASICS APPLIED


What is geochemistry?

Victor Goldschmidt defined the study of geochemistry as: “the laws governing the distribution of the chemical elements and their isotopes throughout the earth”

We are interested in understanding the different ways in which elements move whether in the core, mantle, crust, oceans, sediments, air, space, or other planets…


What do you see now?


What you will know after this class!!

FeS2 + 3.5 O2 + H2O Fe2+ + 2 SO42‐ + 2 H+

Fe2+ + O2 + H+ Fe3+OOH + 2 H+

O2 diffusion

Bacteria/ archea Fe oxidizers, S oxidizers

Light photochemical rxns, phototrophic organisms??

CH2O + FeOOH Fe2+ + CO2

CH2O + SO42‐ HS‐ + CO2

Lecture 2 - Crystal Chemistry 1

Crystal Chemistry

Review: Atoms

Atomic Structure

Bonding


Objectives

To understand that “physical properties” of minerals are closely related to “crystal structure.”

And, crystal structure depends on types of bonding and coordination number.

Then, types of bonding is strongly related to types of atoms whereas coordination number depends on charge+size of atoms.


Atoms

ในอะตอมทเปนกลาง จะมจานวนอเลกตรอนเทากบโปรตอนเสมอ


Classical Model of Atoms


Does electron exist?

ÁÕoo¡ÒÊ¾ºo ieÅç¡µÃo¹ 99% ã¹¾ é¹·ÕèæÃe§Ò


How do electron(s) live in atoms?

From quantum mechanics, electrons have their own orbitals (Ç§o¤¨Ã).Each orbital has unique energy level and ways of orbiting around nucleus.

Each electron has its own set of quantum numbers.

Electron cannot be seen or pictured precisely. Only probability of finding electrons can be calculated.


Quantum Numbers


Energy Levels and Probability of Finding Electrons


Electronic Configuration¡ÒÃäéÃÕÂ§o ieÅç¡µÃo¹ äµ�o§eµiÁÅ§ã¹Ãa aºªaé¹¾Åa§§Ò¹µèíÒÊu´¡ �o¹ æÅ �Çe¾ièÁÃa aº¾Åa§§Ò¹ä»eÃèoÂæ ¨¹¤Ãº¨íÒ¹Ç¹ e‐


µÒÃÒ§¸Òµuä �ä´¡Åu�Á¸Òµu·ÕèÁÕo ieÅç¡µÃo¹Ç§¹o¡Êu æººe ÕÂÇ¡a¹äÇ��ÇÂ¡a¹


Electronic Configuration of Na


Electronic Configuration of Si


Electronic Configuration of Fe


ÙµÒÃÒ§ 4.5 Ë¹�Ò 181‐182 (KH‐Chap4)

« è§ä � List ¡ÒÃ aéÃÕÂ§o ieÅç¡µÃo¹¢o§¸Òµuµ �Ò§æ äÇ �·aé§ËÁ´


Ionization Energy (IE)

¸Òµu·ÕèÁÕ IE µèíÒæ äÁÕæ¹Ço¹ �Á·Õèµ�o§¡ÒÃeÊÕÂo ieÅç¡µÃo¹ä �§�ÒÂ ¨ §oÂÒ¡oÂÙ�e» �¹äooo¹ºÇ¡ ÁÒ¡¡Ç�ÒÊ¶Ò¹a»¡µi


Electronegativity (EN)

¸Òµu·ÕèÁÕ EN ÊÙ§æ µ�o§¡ÒÃ·ÕèäÃaºËÃo´§o ieÅç¡µÃo¹ (oÂÒ¡e» �¹äooo¹·ÕèÁÕ»ÃaüÅº) e¢�ÒÁÒËÒoÂÙ�ã¹Ç§o¤¨ÃÇ§¹o¡Êu´


Trend of Electronegativity


Stable Ions and Oxidation States


Energy of electrons can be used to identify types of elements and/or minerals.

Electron(s) in atom or ions will form “bond” with other atoms/ions.

Bond’s characteristics will govern properties of matter. For example, bonds will determine crystal structure for solids

Importance of Electrons


Use of electron energy to identify elements and/or minerals.

X‐Ray Mineralogy


Hydrogen Atom


Bombarding atoms with high energy electrons.


Characteristic Wavelengths


Use of Characteristic Wavelength

X‐ray diffraction for determination of types of minerals.

Example:

Target = Cu (Copper)

Filter = Ni (Nickel)


X‐ray diffractionLaue Method

Powder Method

θ λ=2 sind n


Importance of Electrons

Energy of electrons can be used to identify types of elements and/or minerals.

Electron(s) in atom or ions will form “bond” with other atoms/ions.

Bond’s characteristics will govern properties of matter. For example, bonds will determine crystal structure for solids


Types of Bonding

Ionic Bond

Covalent Bond

Metallic Bond

Van der Waals, Hydrogen Bonds

e» �¹¾a¹¸ae¤ÁÕÃaËÇ�Ò§oaµoÁ

e» �¹¾a¹¸ae¤ÁÕÃaËÇ�Ò§oaµoÁ æÅa/ËÃo oÁeÅ¡uÅ


Ionic Bond

Two ions are held together by electrostatic forces.

One element gains electron while another loses electron.

This is because the difference in EN is high.

( )20.25 E%Ionic 100 1 e− Δ⎡ ⎤= −⎣ ⎦


Example of Ionic Bond ‐ NaCl

ÁÕ¡ÒÃ¶ �ÒÂe·o ieÅç¡µÃo¹¨Ò¡oaµoÁ¢o§o«e ÕÂÁä»ÊÙ�oaµoÁ¢o§¤ÅoÃÕ¹ e¾ èoãË�¤Ãº¡®oo¡eµµ (Octet Rule)


Covalent Bond

EN of two atoms are similar.

Sharing of outer‐shell electrons occurs to satisfy Duet or Octet rules.


Metallic Bond

Not enough electrons to satisfy Octet rule.

Therefore, sharing of electrons among atoms occur throughout the structure.


Van der Waals Bond

Very weak bond due to the polarization of atoms.

S8 Ring


Hydrogen Bond

Dipole‐Dipole interactions between molecules.

Water Molecule

Ice Crystal


Lecture 3 - Crystal Chemistry (Cont'd) 1

Crystal Chemistry

Ionic Radii, Coordination Number


Examples of ionic radii (A = 10‐10 m)


Atomic/Ionic Radii: How to find them?

Not easy to measure or quantify.May be determined from halving the distance between adjacent atoms (for metal).For ionic solids, radius is calculated from electrostatic force or, nowadays, from x‐ray diffraction.


Electrostatic Force

( )( )2

+ −

=q q

F kd

+ −

′=q q

U kd


ã¹»�¨ uºa¹ ÃaÈÁÕäooo¹äËÒä �¨Ò¡¡ÒÃÇa ÃaÂaË�Ò§ÃaËÇ �Ò§oaµoÁo´Âãª �e·¤¹i¤ x-ray diffraction

« è§ä·íÒ¡ÒÃÇa´ÃaÈÁÕäooo¹¨Ò¡ÊÒÃ»Ãa¡oºËÅÒÂæ ª¹i´ ·ÕèÁÕeÅ¢o¤ooÃ � i¹ªaè¹ (Coordination Number) µ�Ò§æ ¡a¹ æÅ�Ç¹íÒÁÒËÒ¤ �Òe©ÅÕèÂ


Coordination Number (C.N.)

CN = The number of closest neighbors around a specific atom or ion

CN = 2, 3, 4, 6, 8, or 12 depending on the radius ratio between cation(+) and anion(‐)




ÁÕ»�¨ aÂoaäÃ·Õè·íÒãË�¸Òµuª¹ié ÕÂÇ¡a¹ ÁÕeÅ¢o¤ooíe¹ªaè¹äÁ�eËÁo¹¡a¹?

oaµÃÒÊ�Ç¹ÃaÈÁÕ¢o§äooo¹ºÇ¡/Åº ËÃo+

−

RR

A

X

RR

ËÃo



Halite Structure (NaCl)


Fluorite Structure (CaF2)


Theoretical limiting radius ratioCN = 8

+

− = = 0.732A

x

R RR R

A

X X

XX



+

− = = 0.414A

x

R RR R

A

X X

X X



+

− = = 0.155A

x

R RR R


Change in CN due to atomic radii

CN=6

CN=8


ã¹o¤Ã§ÊÃ �Ò§¢o§¼Å¡ äooo¹ºÇ¡ ä¾ÂÒÂÒÁoÂÙ�Ë�Ò§¡a¹ÁÒ¡·ÕèÊuó´Âãª�Çi¸Õ¡ÒÃÊÃ �Ò§ Coordination Polyhedra

« è§äÁÕ¡ÒÃ share ÁuÁ (corner) ËÃo ¢oº (edge) ËÃo Ë¹ �Ò (face)


µaÇoÂ �Ò§ Coordination Polyhedra (¡ÒÃ share ¡a¹¢o§ polyhedra o´Âäooo¹Åº) ¢o§ Tetrahedra

มม ขอบ หนา


µaÇoÂ �Ò§ Coordination Polyhedra (¡ÒÃ share ¡a¹¢o§ polyhedra o´Âäooo¹Åº) ¢o§ Octahedra

มม ขอบ หนา


Pauling’s Rule of Ionic Structure




CN=8, CN=6


CN=4, CN=3





Rule #4:

¶�Òã¹o¤Ã§ÊÃ �Ò§¢o§¼Å ¡ ÁÕäooo¹ºÇ¡ËÅÒÂæ ª¹i oÂÙ��ÇÂ¡a¹ äooo¹ºÇ¡·ÕèÁÕ¢¹ÒéÅç¡Êu´æÅaÁÕ CN µèíÒÊu´ ä

äÁ�ÁÕ¡ÒÃ share polyhedra


ÊÃu» – Pauling’s Rules

µ �o§¡ÒÃãË �e¡i´¤ÇÒÁÊÁ uÅÃaËÇ�Ò§»ÃaüºÇ¡æÅaÅºã¹o¤Ã§ÊÃ �Ò§¢o§¼Å ¡ o´Â¡ÒÃeÃÕÂ§µaÇäµ �o§·íÒãË �»Ãaüª¹ié ÕÂÇ¡a¹oÂÙ�Ë �Ò§¡a¹ÁÒ¡·ÕèÊu´


Bond Strength

Ça´¨Ò¡ü´ËÅoÁeËÅÇ


Bond Strength

Ça´¨Ò¡¤ÇÒÁæ¢ç§


General Rule about Bond Type



Crystal Chemistry (cont’d)

Polymorphism

Isomorphism

Ionic Substitution


Review

1. Radius Ratio (R+/R‐)2. Coordination Number (CN)3. Coordination Polyhedra4. Pauling’s Rules of Ionic Structure

1. Radius ratio determines coordination number.2. Electrostatic valency principle (e.v. = |z|/CN)3. Coordination polyhedra of anion will result in sharing

corners rather than edges or faces.4. For multi‐cations solid, smallest cation with lower C.N.

will not form coordination polyhedra.


Example Calculation of e.v.

ze.v.

C.N.=

e.v. = electrostatic valency

Na+: CN=6

Cl‐: CN=6

1e.v.

6= +

1e.v.

6= −


Exercise #1

Example calculation of e.v.

Example calculation of NaCl size from density


Polymorphism

A substance that can have more than one crystal structures.Why?

Ions making up compounds can crystallize either structure.Important Factors: Temperature & Pressure

Examples?Carbon (C)Al2SiO5

Sulfur (S)Quartz (SiO2)


Sulfur: Temperature

Temperature

“Rhombic” Structure

“Monoclinic” Structure

96 °C Transition Temperature


Carbon: Temperature + Pressure


Al2SiO5: Temperature + Pressure


= Dimorphous


Dimorphous Minerals


Isomorphism

Two substances are “isomorphous” if they have similar crystal structures but different chemical formulae.

OlivineOlivine: (Mg,Fe)2SiO4 has two “end members.”

Mg2SiO4 Fe2SiO4Mg1.3Fe0.7SiO4(forsterite) (fayalite)


Ionic Substitution

Replacement of one cation in crystal structure by another cation.

¡ÒÃæ·¹·Õèäooo¹ºÇ¡ã¹o¤Ã§ÊÃ �Ò§´ �ÇÂäooo¹ºÇ¡oÕ¡µaÇË¹ è§ o´Â·Õèo¤Ã§ÊÃ �Ò§äÁ �e»ÅÕèÂ¹æ»Å§Examples:

olivine (Mg‐Fe)

plagioclase (Ca,Na)


eËµuã´¨§e¡i´¡ÒÃæ·¹·Õè¡a¹ä´ �?

»ÃaüeËÁo¹ËÃoã¡Å �e¤ÕÂ§¡a¹ (µ �Ò§¡a¹äÁ�e¡i¹ 1)Mg(+2) ��. Fe(+2) ËÃ o Ca(+2) ��. Na(+1)

¢¹Ò´¢o§ÃaÈÁÕäooo¹ã¡Å �e¤ÕÂ§¡a¹ (µ �Ò§¡a¹äÁ�e¡i¹ 15%)Mg (0.72 Å), Fe (0.78 Å)

¾a¹¸ae¤ÁÕ¤Å �ÒÂ¤Å§¡a¹ eª�¹ e»�¹¾a¹¸a·ÕèÁÕ¤ÇÒÁe» �¹äooo¹¹i¡¾oæ ¡a¹äooo¹¢o§ Fe2+ ã¹ FeS2 Áa¡äÁ�¶Ù¡æ·¹·Õè´ �ÇÂ Mg2+ e¾ÃÒa¾a¹¸aÁÕ¤ÇÒÁe» �¹o¤ÇÒeÅ¹· �ÊÙ§


Substitution of di‐valent cations in carbonates



Crystal Chemistry (cont’d)

Ionic SubstitutionSolid SolutionExsolution


Ionic Substitution

¡ÒÃæ·¹·Õè¡a¹ä �¢o§oaµoÁ ·íÒãË�e¡i´ÊÒÃÅaÅÒÂ¢o§æ¢ç§ËÃo (Solid Solution) o´Â·Õèo¤Ã§ÊÃ �Ò§¼Å ¡äÁ �e»ÅÕèÂ¹æ»Å§ (æµ �oÒ¨ÁÕ¡ÒÃºiéºÕéÂÇ ¼ié¾ÕéÂ¹ä»¨Ò¡e iÁeÅç¡¹�oÂ)¡ÒÃæ·¹·Õè äe¡i´¢ é¹ä �ËÅÒÂæºº

ª¹i´ æ·¹·Õè¡a¹ä �·aé§ËÁ´ ·u¡ou³ËÀÙÁiæÅa¤ÇÒÁá¹

eª�¹ Olivineª¹i´ æ·¹·Õè¡a¹ä �ºÒ§Ê�Ç¹ª¹i´ æ·¹·Õè¡a¹ä �ºÒ§Ê�Ç¹ e©¾ÒaºÒ§ou³ËÀÙÁi


Albite/Feldspar (Binary System)


Feldspar/Plagioclase (Ternary System)


ou³ËÀÙÁiÊÙ§

ou³ËÀÙÁi»Ò¹¡ÅÒ§


Solid Solution (ÊÒÃÅaÅÒÂ¢o§æ¢ç§)

�A mineral structure in which specific atomic site(s) are occupied in variable proportions by two or more different elements�

�¢o§æ¢ç§ (·Õèe»�¹æÃ �) ·Õè« è§oaµoÁ/äooo¹¶Ù¡æ·¹·Õèä � �ÇÂoaµoÁ/äooo¹µaÇo è¹o´Â·Õèo¤Ã§ÊÃ �Ò§äÁ �e»ÅÕèÂ¹æ»Å§


Types of solid solution

1. Substitutional SS

2. Interstitial SS

3. Omission SS

ã¹¡ÒÃæ·¹·Õèäooo¹«è§äµ�o§ÁÕ¡ÒÃªéªÂ»Ãaü »Ãaü·ÕèÁÒªéªÂäe¢�Òä»oÂÙ�ãÊ¹ª�o§Ç �Ò§ã¹o¤Ã§ÊÃ �Ò§«è§ÁÕoÂÙ�æÅ �Ç

ã¹¡ÒÃæ·¹·Õèäooo¹«è§äÁ�µ�o§ÁÕ¡ÒÃªéªÂ»Ãaü äooo¹ãËÁ �äe¢�Òä»æ·¹·Õèäooo¹eíÁã¹o¤Ã§ÊÃ�Ò§eíÁ oÒë» �¹¡ÒÃæ·¹·Õèæººe´ÕèÂÇæ ËÃoæººe» �¹¤Ù�

ÁÕ¡ÒÃæ·¹·Õèäooo¹»Ãaü¹ �oÂÊo§µaÇ´ �ÇÂ»Ãaü·ÕèÁÒ¡¡Ç �Òe¾ÕÂ§Ë¹ è§µaÇ ·íÒãË�e¡i´ª�o§Ç �Ò§ã¹o¤Ã§ÊÃ�Ò§


Substitutional SS

ÁÕ·aé§æººæ·¹·Õèä �·aé§ËÁ´ ËÃoºÒ§Ê �Ç¹ «è§¢¹Ò´¢o§äooo¹äe» �¹µaÇ¡íÒË¹´Ç�Òäe¢�Òä»æ·¹·Õèä �æººäË¹


Interstitial SS (การแทนทในชองวางทมอยแลว)

¡ÒÃæ·¹·Õè 2Si4+ ´ �ÇÂ Al3+ æÅa Be2+ äÁÕ»Ãaü¢Ò´ä» +3 á§¹aé¹äooo¹¢¹Ò´ãË�eª�¹ 3K+ ÊÒÁÒÃ¶e¢�Òä»oÂÙ�ã¹o¤Ã§ÊÃ �Ò§ o´Âäe¢�Òä»oÂÙ�ã¹ª�o§Ç �Ò§·ÕèÁÕoÂÙ�æÅ �Ç


Omission SS

e» �¹¡ÒÃæ·¹·Õèæ ·íÒãË�e¡i´ª�o§Ç �Ò§ (vacancy) ã¹o¤Ã§ÊÃÃ �Ò§ «è§Áa¡e¡i´¨Ò¡¡ÒÃæ·¹·Õè¢o§äooo¹ºÇ¡»Ãa¨ uµèíÒæ Êo§µaÇ¢é¹ä» �ÇÂäooo¹ºÇ¡»Ãa¨ uÊÙ§¡Ç�Ò¨íÒ¹Ç¹Ë¹è§µaÇ eª�¹ ¡ÒÃæ·¹·Õè¢o§ 2K+ �ÇÂ Pb2+ ã¹æÃ� microcline (KAlSi3O8)

+ + ++ = +2K K Pb


Solid Solution (ÊÒÃÅaÅÒÂ¢o§æ¢ç§)

¶ �Òe¡i´·Õèo u³ËÀÙÁiÊÙ§ oaµoÁäeÃÕÂ§µaÇ¡a¹äÁ�e»�¹ÃaeºÕÂº ÊÒÃÅaÅÒÂ¢o§æ¢ç§äeÃÕÂ¡Ç �Ò disordered SS¶ �Òe¡i´·Õèo u³ËÀÙÁiµèíÒ oaµoÁäeÃÕÂ§µaÇ¡a¹e»�¹ÃaeºÕÂºÁÒ¡¢é¹ ÊÒÃÅaÅÒÂ¢o§æ¢ç§·Õèe¡i´ ³ o u³ËÀÙÁiµèíÒæ äeÃÕÂ¡Ç �Ò ordered SS


Order-Disorder


Exsolution

ÊÒÃÅaÅÒÂ¢o§æ¢ç§·Õèe¡i´ ³ o u³ËÀÙÁiÊÙ§æ (e¡i´ä �e¾ÃÒao¤Ã§ÊÃ�Ò§e¡i´¡ÒÃ¢ÂÒÂµaÇ) æµ �eÁèo u³ËÀÙÁiÅ´Å§ äe¡i´¡ÒÃæÂ¡µaÇoo¡e» �¹¼Å ¡Êo§ª¹i´ (ËÃoÁÒ¡¡Ç�Ò¹aé¹) oo¡¨Ò¡¡a¹

A process whereby an initially homogeneous solid solution separates into two (or possibly more) distinct crystalline minerals without addition or removal of material from the sytem


Albite/Feldspar (Binary System)

solvus


Exsolution: example


Mineral Chemistry

Chemical Formulae of the Minerals


Recalculation of chemical analysis

æÃ �ÁÕÊÙµÃe¤ÁÕ·Õèæ¹ �¹o¹ « è§ÊÒÁÒÃ¶e»ÅÕèÂ¹æ»Å§ä´ �ã¹Ç§¨íÒ¡a´ o´Â·Õèo¤Ã§ÊÃ �Ò§äÁ �e»ÅÕèÂ¹æ»Å§»�ËÒ¡ç¤o ËÅa§¨Ò¡Çie¤ÃÒaË�æÃ �µaÇË¹ è§æ æÅ�Ç¾ºÇ �ÒÁÕ¸Òµ uoÂÙ�ËÅÒÂæ ª¹i´ ä·ÃÒºÊÙµÃe¤ÁÕ¢o§æÃ �µaÇ¹aé¹ä´ �oÂ �Ò§äÃ?

oÒ¨Çie¤ÃÒaË�o´Âãª�e·¤¹i¤ x-ray fluorescent

spectroscopy


Example: Chalcopyrite (CuFeS2)

Cu:Fe:S = 1:1:2 หรอ CuFeS2


Example: Sphalerite (Zn,Fe,Mn,Cd)S

เปน Solid Solution ในโครงสราง Sphalerite


Example: Gypsum (CaSO4·2H2O)

ผลการวเคราะห สวนใหญจะออกมาในรปของ oxide ดงเชน กรณของแรยปซม


ã¹¡Ã³Õ·Õèe» �¹ solid solution ¡ÒÃ¤íÒ¹Ç³ËÒÊÙµÃe¤ÁÕËÃoo§¤ �»Ãa¡oº¢o§æµ �Åa end members äãª � íÒ¹Ç¹oo¡«ie¨¹e» �¹ËÅa¡

µaÇoÂ �Ò§eª �¹ Olivine, Pyroxene, æÅa Amphiboleso´Â¼Å¡ÒÃÇie¤ÃÒaË�»ÃiÁÒ³¸ÒµuäoÂÙ�ã¹ÃÙ»¢o§ wt% oo¡ä«´ �


Example: Olivine Solid Solution

แร Olivine เปนสารละลายของแขงทประกอบดวย 2 end members ไดแก fosterite & fayalite

Olivine = Fo57Fa43


Pyroxene Solid Solution

Pyroxene = Wo50.3En42.4Fs7.3

Ca(Mg,Fe)(Si,Al)2O6

Lecture 6 - Physical Properties of Minerals 1

Physical Properties of Minerals

Types of ElementsChemical BondingCrystal Structure

¤u³ÊÁºaµi·Ò§¡ÒÂÀÒ¾¢o§æÃ �¢ é¹oÂÙ�¡aº» �¨ aÂµ �oä»¹Õé


Physical Properties - ¤u³ÊÁºaµi·Ò§¡ÒÂÀÒ¾

Cleavage, Parting, & FractureHardnessTenacitySpecific gravityColor

StreakLusterChatoyancy & AsterismElectrical propertyMagnetic property


Cleavage

Cleavage = ¡ÒÃæµ¡e»�¹Ë¹�ÒeÃÕÂº¢o§æÃ �µÒÁÃa¹Òº·ÕèÁÕæÃ§Â éË¹ÕèÂÇã¹o¤Ã§¼Å¡o �o¹·ÕèÊu´ (ÃaÂaÃaËÇ�Ò§Ãa¹Òº = ¡Ç�Ò§)


¡ÒÃæµ¡µÒÁæ¹Ç cleavage äÁ �¨íÒe»�¹µ�o§ÊaÁ¾a¹¸ �¡aºÃÙ»¼Å¡ËÃoÃa¹Òº¢o§ crystal growth ¡çä �

Cleavage vs. Growth plane

Growth Plane = Ãa¹Òº¢o§¼Å¡·ÕèË¹ �ÇÂeÅç¡æ ÁÒµ�oæ ¡a¹¨¹¡ÅÒÂe»�¹¼Å¡¢¹Ò´ãË�


Parting & Fracture

Parting: ËÃ oæ¹ÇæÂ¡¢o§æÃ � « è§Áa¡äe¡i´¨Ò¡¡ÒÃ·Õè¡ �o¹æÃ �e¡i´¡ÒÃ exsolution (ÊÒÃÅaÅÒÂ¢o§æ¢ç§æÂ¡µaÇoo¡¨Ò¡¡a¹e»�¹ªaé¹æ) æÅ�ÇæÃ �Êo§µaÇ¹ÕéæÂ¡oo¡¨Ò¡¡a¹

Fracturing: ã¹¡Ã³Õ·Õè¾a¹¸ae¤ÁÕÁÕ¤ÇÒÁæ¢ç§æÃ§e· �Òæ ¡a¹·u¡·iÈ·Ò§ ¡ÒÃæµ¡¢o§æÃ � aäÁ�ÁÕ·iÈ·Ò§·Õèæ¹ �¹o¹ eª�¹ æÃ �¤Çoµ« �eÁèoæµ¡ääÁ�ÁÕ·iÈ·Ò§ËÅa¡


Hardness

¤ÇÒÁæ¢ç§ËÃo¤ÇÒÁ·¹·Ò¹µ �o¡ÒÃ¢Ù´¢ �Ç¹ (o´Â·ÕèæÃ �äÁ�ÁÕ¡ÒÃæµ¡oo¡¨Ò¡¡a¹)

¤ÇÒÁæ¢ç§e»�¹¤u³ÊÁºaµi·Õè¢ é¹oÂÙ�¡aº¾a¹¸ae¤ÁÕ æÅa¡ÒÃäéÃÕÂ§äooo¹ËÃo¡Åu�Áäooo¹ã¹o¤Ã§ÊÃ �Ò§¼Å¡


Tenacity

BrittleMalleableSectileDuctileFlexibleElastic

ËÁÒÂ¶ §¤ÇÒÁ·¹·Ò¹µ �o¡ÒÃ·uº ¡ÒÃº´ ¡ÒÃºi ÏÅÏ « è§¢ é¹oÂÙ�¡aºª¹i´¢o§¾a¹¸ae¤ÁÕã¹o¤Ã§ÊÃ �Ò§

¾a¹¸aäooo¹i¡¾a¹¸ao¤ÇÒeÅ¹·� ¾a¹¸aæÇ¹eóÇÒÅÊ �¾a¹¸aoÅËa


Specific Gravity

¤ÇÒÁ¶ �Ç§¨íÒe¾Òa ¤ o¤ÇÒÁË¹Òæ¹ �¹¢o§æÃ � ËÒÃ �ÇÂ ¤ÇÒÁË¹Òæ¹ �¹¢o§¹éíÒ·Õè 4o C

¤ÇÒÁ¶ �Ç§¨íÒe¾Òa¢ é¹oÂÙ�¡aº(1) ª¹i´¢o§oaµoÁ/äooo¹(2) ¡ÒÃäéÃÕÂ§oaµoÁ/äooo¹ã¹

o¤Ã§ÊÃ �Ò§¼Å¡


ColorÊÕ¢o§æÃ � e¡i´¢ é¹¨Ò¡¡ÒÃ·ÕèoieÅç¡µÃo¹ã¹oaµoÁæÅaã¹¾a¹¸ae¤ÁÕ ¢o§¸ÒµuoÅËa·ÃÒ¹Êiªa¹ (Ê�Ç¹ãË�e»�¹ÊÒÃÁÅ·i¹) ÁÕ¡ÒÃe»ÅÕèÂ¹æ»Å§ orbital ËÃoe»ÅÕèÂ¹æ»Å§Ãa aº¾Åa§§Ò¹ (oÒ¨ÁÕ¡ÒÃ Ùé¢ �Òä»ËÃo¤ÒÂoo¡ÁÒ) ·íÒãË �e¡i´æÊ§ÊÕµ�Ò§æ

Crystal Field Theory


Electrical Properties

ConductorSemi-ConductorNon-Conductor

Piezoelectric ÊÒÁÒÃ¶¹íÒä¿¿�Òä � eÁ èoãË �¤ÇÒÁá¹æ¡�¡�o¹æÃ�

Pyroelectric ÊÒÁÒÃ¶¹íÒä¿¿�Òä �eÁ èoãË �¤ÇÒÁÃ�o¹e»�¹¤u³ÊÁºaµi·Õè¢ é¹oÂÙ�¡aº¾a¹¸a

e¤ÁÕ æÅaª¹i´¢o§oaµoÁ/äooo¹ ¶ �ÒÁÕoieÅç¡µo¹·Õèe¤Åèo¹·Õèä»ÁÒoÂ�Ò§oiÊÃa eª�¹¾a¹¸aoÅËa ¡çä¹íÒä¿¿�Òä �


Magnetic Property

Ferromagnetic � æÁ �eËÅç¡ Ù´µi´ä �Paramagnetic � æÁ �eËÅç¡Ù´Âa§äÁ �µi´ æµ�eÁ èoeoÒä»ãÊ�ã¹

Ê¹ÒÁæÁ �eËÅç¡ ä¡ÅÒÂe»�¹æÁ �eËÅç¡o �o¹æ ä´ �Diamagnetic� äÁ �ÊÒÁÒÃ¶·íÒãË�e»�¹æÁ �eËÅç¡ä �eÅÂ

e»�¹¤u³ÊÁºaµi·Õè¢ é¹oÂÙ�¡aºª¹i¢o§oaµoÁ/äooo¹ æÅao´Âe©¾ÒaoÂ �Ò§Âiè§ ¡ÒÃäéÃÕÂ§oieÅç¤µÃo¹ã¹ orbitals « è§ä¢ é¹oÂÙ�¡aº magnetic quantum number


Examples

Ferromagnetic = Magnetite (Fe3O4)Paramagnetic =

Olivine (Mg,Fe)SiO4

Pyroxene (Ca,Na)(Mg,Fe,Al)(Al,Si)2O6

paramagnetic

Lecture 7 - Thermodynamics I 1

ThermodynamicsThermodynamics o u³Ë¾ÅÈÒÊµÃ�

Systems vs. SurroundingsIntensive vs. Extensive PropertiesFundamental Laws of Thermodynamics


e·oÃ�oÁä´¹ÒÁi¡Ê �e¤ÁÕ·íÒäÁ¹éíÒ¡ÅÒÂe»�¹¹éíÒæ¢ç§ËÃ o¹éíÒæ¢ç§ÅaÅÒÂ¡ÅÒÂe»�¹¹éíÒ ÁÕ»�¨ aÂoaäÃÁÒe¡ÕèÂÇ¢ �o§?·íÒäÁ¡ÒÃ·o´ä¢ �e ÕÂÇ (»¯ i¡iÃ iÂÒ·Õè·íÒãË�ä¢ �Êu¡) ¨§e»�¹»¯ i¡iÃ iÂÒ·ÕèÂ �o¹¡Å aºäÁ �ä �?·íÒäÁÊÒÃe¤ÁÕºÒ§ª¹i´ÅaÅÒÂ¹éíÒæÅ �Çou³ËÀÁ i¢o§¹éíÒe»ÅÕèÂ¹ä»eËµuã´æÁ¡ÁÒµaÇe ÕÂÇ¡ a¹ æµ�µ¡¼Å ¡·Õè¤ÇÒÁ´ a¹µ�Ò§¡a¹äãË�æÃ �·ÕèäÁ �eËÁo¹¡a¹?·íÒäÁe¾ªÃ« è§e»�¹¤ÒÃ �ºo¹·ÕèeÊ¶ÕÂÃ ³ ¤ÇÒÁ´ a¹ÊÙ§æ ¨§oÂÙ�º¹¼iÇoÅ¡« è§ÁÕ¤ÇÒÁ´ a¹e¾ÕÂ§ 1 ºÃÃÂÒ¡ÒÈ ä �o´ÂäÁ �e»ÅÕèÂ¹e»�¹æ¡Ãä¿µ�

¤íÒ¶ÒÁeËÅ�Ò¹ÕéÊÒÁÒÃ¶µoºä �o´Âãª�ËÅa¡¡ÒÃ·Ò§e·oÃ �oÁä´¹ÒÁi¡Ê�e¤ÁÕ


Thermodynamics e¡ÕèÂÇ¢�o§¡ aº¸Ã³ÕÇi·ÂÒoÂ �Ò§äÃ?

¡ÒÃµ¡¼Å ¡¢o§æÁ¡ÁÒe»�¹æÃ �µ�Ò§æ ä¶Ù¡¤Çº¤uÁo´Âo§¤�»Ãa¡oº¢o§æÁ¡ÁÒ (Composition)¾Åa§§Ò¹æÅa¡ÒÃ¶�ÒÂe·¾Å a§§Ò¹ (Energy)ou³ËÀÙÁ i æÅa¤ÇÒÁ´ a¹ (Temperature & Pressure)

o´ÂäÁÕ¡ÒÃ¶�ÒÂe·¾Å a§§Ò¹ÃaËÇ�Ò§Ãaºº¡aºÊiè§æÇ´Å �oÁ ã¹¢³a·ÕèÊÊÒÃÀÒÂã¹ÃaººäÁÕ¡ÒÃe»ÅÕèÂ¹ÃÙ»ËÃ oe»ÅÕèÂ¹Ê¶Ò¹a¡ÒÃ¼u¾ a§·íÒÅÒÂ (chemical weathering) ¢o§Ëi¹ËÃ oæÃ �º¹¼iÇoÅ¡ e¡i´¢ é¹e¾ÃÒaoaäÃ? ·íÒäÁæÃ �ºÒ§µaÇ¶§¶Ù¡¼u¾ a§·íÒÅÒÂä �§ �ÒÂ ã¹¢³a·ÕèæÃ �oÕ¡µaÇË¹è§ä·¹·Ò¹µ �o¡ÒÃ¼u¾ a§ÁÒ¡¡Ç �Ò

ãª�o¸ iºÒÂ �ÊÁ uÅ� e¤ÁÕ


System vs. Surroundings

Ãaºº »Ãa¡oº´ �ÇÂÊÊÒÃª¹ i µ�Ò§æ »a»¹¡a¹oÂÙ� ËÒ¡ÊÊÒÃÁÕ¢oºe¢µ·ÕèÁo§eËç¹ä´ �ªaé¨¹ eÃÒäeÃÕÂ¡Áa¹Ç �Òe»�¹ phase Ë¹ è§ «è§ÃaººË¹ è§æ ÁÕä´ �ËÅÒÂ phase eª�¹ ÃaººoÒ¨»Ãa¡oº´ �ÇÂ æÃ� Ëi¹ ¹éíÒ oÒ¡ÒÈ æÁ¡ÁÒ ÏÅÏ « è§ÊÊÒÃæµ �Åa phase ·ÕèoÂÙ�¡a¹oÂ�Ò§ �ÊÁúÅ� ¡çäÁÕÊÒÃe¤ÁÕ·Õè»Ãa¡oº¢é¹ÁÒ¨Ò¡Ë¹ �ÇÂËÅa¡e¾ÕÂ§Ë¹ è§ËÃoËÅÒÂæ Ë¹�ÇÂ «è§æµ �ÅaË¹ �ÇÂeÃÕÂ¡Ç �Ò component


ª¹i ¢o§ �Ãaºº� ã¹æ§ �¢o§e·oÃ�oÁä´¹ÒÁi¡Ê �

Ãaººe»�´ (open system)ÁÕ¡ÒÃæÅ¡e»ÅÕèÂ¹· aé§ÁÇÅÊÒÃæÅa¾Åa§§Ò¹¡ aºÊiè§æÇ´Å�oÁÃaºº» �´ (closed system)

ÁÕ¡ÒÃ¶ �ÒÂe·¾Åa§§Ò¹e¢ �Ò-oo¡Ãaºº æµ�äÁ�ÁÕ¡ÒÃ¶ �ÒÂe·ÁÇÅÊÒÃÃaººæÂ¡µ aÇ (isolated system)Ãaºº·ÕèäÁ�ÁÕ¡ÒÃ¶ �ÒÂe·· aé§ÁÇÅÊÒÃËÃ o¾Åa§§Ò¹


µ aÇoÂ�Ò§¢o§ �Ãaºº�


How to describe �system�?

eÇÅÒ¾Ù ¶§Ãaºº eÃÒäãª�µ aÇæ»ÃÁÒo iºÒÂ « è§µ aÇæ»ÃeËÅ�Ò¹ÕéeÃÕÂ¡Ç �Ò �¿�§¡ �ªa¹º�§Ê¶Ò¹a� ËÃ o Function of State « è§e»�¹¤u³ÊÁºaµ ie©¾Òaµ aÇ¢o§Ãaºº ä �æ¡ � ¨íÒ¹Ç¹oÁÅ o u³ËÀÙÁi ¤ÇÒÁ´ a¹ eo ¹·ÒÅ» � eo ¹o·Ã» � ¾Åa§§Ò¹oiÊÃa ¾Åa§§Ò¹ÀÒÂã¹ ÏÅÏ¤u³ÊÁºaµ ieËÅ�Ò¹Õé æº �§oo¡e»�¹Êo§»ÃaeÀ· ä´�æ¡ �

¤u³ÊÁº aµi·Õèe»�¹ Extensive (¢ é¹oÂÙ�¡aº¢¹Ò´¢o§Ãaºº)¤u³ÊÁº aµi·Õèe»�¹ Intensive (äÁ �¢ é¹¡aº¢¹Ò´¢o§Ãaºº)


Intensive Properties

äÁ�¢ é¹¡ aº¢¹Ò´¢o§Ãaºº ¡Å�ÒÇ¤o ¶ �ÒÃaººÁÕ¢¹Ò´ãË�¢ é¹ ËÃ oÁÕ»Ã iÁÒ³ÊÒÃÁÒ¡¢ é¹ äÁÕ¤u³ÊÁºaµ ieËÅ�Ò¹Õé¡ç aäÁ�e»ÅÕèÂ¹ä» eÃÒeÃÕÂ¡Ç �Ò äÁ�ÁÕ¤u³ÊÁºaµ iæºº additiveeª�¹ o u³ËÀÙÁi¢o§Ãaºº ääÁ�ãª�o u³ËÀÙÁi¢o§·u¡æ ÊÊÒÃã¹ÃaººÃÇÁ¡ a¹ËÃ o ¤ÇÒÁe¢ �Á¢ �¹¢o§e¡Åoã¹ÊÒÃÅaÅÒÂ äÁÕ¤ �Ò¤§·Õè äÁ�Ç �ÒÊÒÃÅaÅÒÂ¹ aé¹æ äÁÕ¶Ù¡æº �§oo¡ä»ãË�ÁÕ»Ã iÁÒ³·Õèæµ¡µ �Ò§¡ a¹


Extensive Properties

¢ é¹¡ aº¢¹Ò´¢o§Ãaºº ¡Å�ÒÇ¤o ¶ �ÒÃaººÁÕ¢¹Ò´ãË�¢ é¹ ËÃ oÁÕ»Ã iÁÒ³ÊÒÃÁÒ¡¢ é¹ äÁÕ¤u³ÊÁºaµ ieËÅ�Ò¹Õée¾ ièÁ¢ é¹ eÃÒeÃÕÂ¡Ç �ÒÁÕ¤u³ÊÁºaµ iæºº additive (ºÇ¡)eª�¹ ¨íÒ¹Ç¹oÁÅ¢o§¸Òµuo«e´ÕÂÁã¹Ãaºº äe· �Ò¡ aº¨íÒ¹Ç¹ oÁÅ¢o§¸Òµuo«e´ÕÂÁã¹æµ �Åa phase ÃÇÁ¡ a¹ËÃ o »Ã iÁÒ³¾Åa§§Ò¹ÀÒÂã¹Ãaºº äe· �Ò¡ aº ¾Åa§§Ò¹ÀÒÂã¹¢o§æµ �ÅaÊÊÒÃã¹ÃaººÃÇÁ¡ a¹ e»�¹µ �¹


Example of Properties

Mole (n)Volume (V)Internal Energy (E)Enthalpy (H)Gibbs Free Energy (G)

Temperature (T)Pressure (P)Concentration (C)Chemical Potential (μ)

EXTENSIVE INTENSIVE


µ aÇoÂ �Ò§¡ÒÃãª �¿ �§¡ �ª a¹º �§Ê¶Ò¹a (Function of State)

= ( , )V f T P

=

∂ ∂⎛ ⎞ ⎛ ⎞= +⎜ ⎟ ⎜ ⎟∂ ∂⎝ ⎠ ⎝ ⎠

( , )

P T

V f T P

V VdV dT dPT P

=nRTVP

»ÃiÁÒµÃ¢o§æ¡ �Êã¹·�oÊÙº¢é¹oÂÙ�¡ aºo u³ËÀÙÁiæÅa¤ÇÒÁ a¹

eÃÒoÂÒ¡·ÃÒºÇ �Ò æ¡ �Êã¹o u Á¤µi (PV=nRT) ¨íÒ¹Ç¹ n oÁÅäÁÕ»ÃiÁÒµÃe»ÅÕèÂ¹ä»e·�Òã´ ¶ �Ò¤ÇÒÁ a¹æÅao u³ËÀÙÁie»ÅÕèÂ¹ä» ΔP æÅa ΔT µÒÁÅíÒ aº

2

P

T

V nRT PV nRTP P

∂⎛ ⎞ =⎜ ⎟∂⎝ ⎠∂⎛ ⎞ = −⎜ ⎟∂⎝ ⎠

= −

Δ ≈ Δ − Δ

2

2

nR nRTdV dT dPP PnR nRTV T PP P


µ aÇoÂ�Ò§¿ �§¡ �ª a¹º�§Ê¶Ò¹a (Function of State)

=

=

=

= ×

Δ = +

Δ = −

-1 -1

5 -2

-2

1 mol

8.3143 J mol K

298 K

1.01325 10 N m

30 K

5,000 N m

n

R

T

P

T

P

Δ ≈ Δ − Δ2

nR nRTV T PP P

¶ �Òæ¡ �Êã¹o u´Á¤µi 1 oÁÅã¹Ãaºº» �´ (e iÁÁÕo u³ËÀÙÁi 298 K æÅa¤ÇÒÁa¹ 1.01325×105 N/m2) ÁÕo u³ËÀÙÁie¾ ièÁ¢é¹ 30 K æÅa¤ÇÒÁ a¹

Å´Å§ 5,000 N/m2 ¨§¤íÒ¹Ç³ËÒ»ÃiÁÒµÃ¢o§æ¡ �Ê·Õèe»ÅÕèÂ¹ä»

−

Δ ≈ + − −× ×

= + ×

= +

5 5 2

3 3

(1)(8.3143) (1)(8.3143)(298)( 30) ( 5000)1.01325 10 (1.01325 10 )3.67 10 m

3.67 L

V

æ¡ �ÊäÁÕ»Ã iÁÒµÃe¾ ièÁ¢ é¹ 3.67 ÅiµÃ


Laws of Thermodynamics

Zeroth LawThermodynamic Equilibrium (¶ �ÒÃaººÊo§ÃaººoÂÙ�µ i´¡ a¹æÅaÁÕo u³ËÀÙÁie· �Ò¡ a¹ eÃÕÂ¡Ç �ÒoÂÙ�ã¹ÊÀÒÇaÊÁúÅ·Ò§e·oÃ �oÁä´¹ÒÁi¡Ê� « è§»Ãa¡oº´ �ÇÂÊÁúÅ· aé§ÊÒÁæºº

Thermal EquilibriumMechanical EquilibriumChemical Equilibrium



First LawConservation of Energy ËÃo¡®o¹uÃ a¡É�¾Åa§§Ò¹ « è§¡Å�ÒÇÇ �Ò ¾Åa§§Ò¹ÀÒÂã¹Ãaºº·Õèe»ÅÕèÂ¹æ»Å§ä» (dE) äe· �Ò¡ aº¾Åa§§§Ò¹¤ÇÒÁÃ �o¹·ÕèÃaºº´Ù e¢ �Òä»ËÃ o¤ÒÂoo¡ÁÒ (dQ) ºÇ¡¡ aº»Ã iÁÒ³§Ò¹·ÕèÃaºº·Õè¡Ãa·íÒµ �oËÃ o¶Ù¡¡Ãa·íÒo´ÂÊiè§æÇ´Å�oÁ (dW)

dE = dQ - dWÃaºº·íÒ§Ò¹ dW ÁÕe¤Ãèo§ËÁÒÂe»�¹ �ºÇ¡�Ãaºº Ù´¤ÇÒÁÃ�o¹ dQ ÁÕe¤Ãèo§ËÁÒÂe»�¹ �ºÇ¡�ÃaººÁÕ¾Åa§§Ò¹ÀÒÂã¹e¾ ièÁ¢é¹ dE äÁÕ¤�Òe»�¹ �ºÇ¡�

dW = PdV



Second Law ¡®·Õèe¡ÕèÂÇ¡aº¤ÇÒÁäÃ �ÃaeºÕÂº¢o§Ãaºº « è§¤ÇÒÁäÃ �ÃaeºÕÂº¹Õé ºo¡ä � �ÇÂ»Ã iÁÒ³·ÕèeÃÕÂ¡Ç �Ò �eo ç¹o·Ã» �� (Entropy, S)

ÃaººæÅaÊiè§æÇ´Å�oÁ ä¾ÂÒÂÒÁ´íÒe¹ i¹ä»ã¹·iÈ·Ò§·Õèe¾ ièÁ¤ÇÒÁäÁ�e»�¹ÃaeºÕÂº ËÃ oe¾ ièÁeo ç¹o·Ã» �

ΔStotal = ΔSsys + ΔSsurr ≥ 0


Entropy, S

ã¹¡ÃaºÇ¹¡ÒÃËÃ o» i¡ iÃ iÂÒ·Õè¼a¹¡Åaºä´ �: ¡ÒÃe»ÅÕèÂ¹æ»Å§eo ç¹o·Ã» �e· �Ò¡ aº¤ÇÒÁÃ �o¹·Õè¶ �ÒÂe·e¢ �Ò-oo¡¨Ò¡ÃaººËÒÃ´ �ÇÂo u³ÀÙÁiÊaÁºÙÃ³�

ã¹¡ÃaºÇ¹¡ÒÃËÃ o» i¡ iÃ iÂÒ·Õè¼a¹¡ÅaºäÁ�ä´ � (« è§» i¡ iÃ iÂÒËÃ o¡ÃaºÇ¹¡ÒÃÊ�Ç¹ãË� ae»�¹æºº¹Õé)

dS = dQ/T

dS ≥ dQ/T



Third Law ³ o u³ËÀÙÁ i 0 K (e¤ÅÇ i¹) ¡ÃaºÇ¹¡ÒÃ·u¡oÂ�Ò§ËÂu´ËÁ´ æÅa¤ �Òeo ¹o·Ã» � (S) ËÃo¤ÇÒÁäÃ �ÃaeºÕÂº¢o§ÃaººÁÕ¤ �Òe» �¹ÈÙ¹Â�

ST = 0 K = 0

�eo ç¹o·Ã»�� e»�¹ extensive properties e¾ÕÂ§ª¹ ié ÕÂÇã¹·Ò§e·oÃ �oÁä´¹ÒÁi¡Ê�·ÕèÊÒÁÒÃ¶ËÒ¤ �Òä � Ê�Ç¹»Ã iÁÒ³o è¹æ ¹ aé¹ËÒ¤ �Òä �e¾ÕÂ§ ¤ÇÒÁe»ÅÕèÂ¹æ»Å§ËÃ o Δ eª�¹ ΔQ, ΔE

Lecture 8 - Thermodynamics II 1


Heat of Reaction/Transformation (Q)Heat Capacity (Cp or Cv)Enthalpy (H)

e¹ �¹e©¾Òa·Õèä¹íÒÁÒãª�¡ aº¸Ã³ÕÇ i·ÂÒ


Heat Exchange due to Reaction or Transformation (Q)

¤ÇÒÁÃ �o¹·ÕèÁÕ¡ÒÃ¶ �ÒÂe·e¢ �Ò-oo¡¨Ò¡Ãaºº æÅ�Ç·íÒãË�e¡ i¡ÒÃe»ÅÕèÂ¹æ»Å§ eª�¹¡ÒÃe»ÅÕèÂ¹æ»Å§Ê¶Ò¹a¨Ò¡¢o§æ¢ç§ä»e»�¹¢o§eËÅÇ ËÃ o¤ÇÒÁÃ �o¹·Õè¶ �ÒÂe·e¢ �Ò-oo¡Ãaºº« è§·íÒãË�o u³ËÀÙÁi¢o§Ãaººe»ÅÕèÂ¹ä»« è§»Ã iÁÒ³¤ÇÒÁÃ �o¹¹ÕéÊÒÁÒÃ¶ �Ç a � ä´ � ËÃ o ÊÒÁÒÃ¶¤íÒ¹Ç³ä´ � Ò¡¤ÇÒÁÃ �o¹¨íÒe¾Òa (Heat Capacity, C)


Heat Capacity (C)

¤ÇÒÁÃ �o¹¨íÒe¾Òa = »Ã iÁÒ³¤ÇÒÁÃ �o¹ (µ �ooÁÅ) ·Õè¶ �ÒÂe·e¢ �Ò-oo¡¨Ò¡Ãaºº æÅ�Ç·íÒãË�ÊÊÒÃÁÕo u³ËÀÙÁie»ÅÕèÂ¹ä» 1 K

¶ �Òo u³ËÀÙÁi¢o§ÊÒÃe»ÅÕèÂ¹ä» æµ �»Ã iÁÒµÃ (V) äÁ�e»ÅÕèÂ¹

¶ �Òo u³ËÀÙÁi¢o§ÊÒÃe»ÅÕèÂ¹ä» æµ �¤ÇÒÁ´ a¹ (P) äÁ�e»ÅÕèÂ¹

C = dQ/dT

Cv = dE/dT

Cp = dH/dT

สตรทวไป

ทางธรณวทยาสวนใหญจะใช Cp


Heat Capacity (C)

¤ÇÒÁÊaÁ¾ a¹ �ÃaËÇ �Ò§ Cp æÅa CV

o´Â»¡µ iæÅ�Ç ¤ �Ò Cp ä¢ é¹oÂÙ�¡ aºo u³ËÀÙÁi (T)

Cp = CV + TVα2/β

Cp = a + bT + cT-2 + dT-0.5

α = สมประสทธการขยายตวเนองจากความรอนβ = สมประสทธการถกบบอดเนองจากความดน

ã¹¡Ã³Õ¢o§æ¡ �Êã¹ou´Á¤µi Cp = CV + R

Cp = a + bT - cT-2หรอ


Enthalpy (H)

ËÁÒÂ¶§¾Å a§§Ò¹¤ÇÒÁÃ �o¹·ÕèÊaÊÁoÂÙ�ã¹o¤Ã§Ã �Ò§¼Å ¡

o´Â»¡µiæÅ �Ç ¤ �Òeoç¹·ÒÅ»� (H) äËÒ¤ �ÒäÁ �ä � eÃÒËÒä �e¾ÕÂ§¤ÇÒÁe»ÅÕèÂ¹æ»Å§¢o§eoç¹·ÒÅ»�ËÃ o ΔH eª �¹

¡ÒÃe»ÅÕèÂ¹æ»Å§¢o§eoç¹·ÒÅ» � (¾Åa§§Ò¹·Õè Ù´ËÃo¤ÒÂ) ¨Ò¡» i¡iÃiÂÒe¤ÁÕ ³ ou³ËÀÙÁ i¤§·Õè¡ÒÃe»ÅÕèÂ¹æ»Å§¢o§eoç¹·ÒÅ» � (¾Åa§§Ò¹·Õè Ù´ËÃo¤ÒÂ) ¨Ò¡¡ÒÃe»ÅÕèÂ¹æ»Å§·Õèou³ËÀÙÁ iäÁ �¤§·Õè

H = E + PV


¡ÒÃe»ÅÕèÂ¹æ»Å§¢o§eo ç¹·ÒÅ» � ΔH

ã¹¡Ã³Õ·Õèo u³ËÀÙÁi �¤§·Õè� ËÒä �¨Ò¡eo ç¹·ÒÅ» �¢o§¡ÒÃe¡ i

ã¹¡Ã³Õ·Õèo u³ËÀÙÁiäÁ�¤§·Õè äµ �o§ãª�¤ �Ò Cp ÁÒª �ÇÂ¤íÒ¹Ç³ΔHf

o ËÁÒÂ¶§eo ç¹·ÒÅ» �¢o§¡ÒÃe¡i´ (Enthalpy of Formation)

2

1 2

1

T

T T pT

H H H C dTΔ = − = ∫สาหรบกรณทความดนคงท

ΔHr = Σ(ΔHfo)products � Σ(ΔHf

o)reactants


µ aÇoÂ�Ò§¡ÒÃ¤íÒ¹Ç³eo ç¹·ÒÅ» �

¨§¤íÒ¹Ç³ËÒ¤ �Òeo ç¹·ÒÅ» �·Õèe»ÅÕèÂ¹æ»Å§ä» (ËÃ o¾Åa§§Ò¹¤ÇÒÁÃ �o¹·Õè¶ �ÒÂe·e¢ �Ò-oo¡Ãaºº) eÁèoãË�¤ÇÒÁÃ �o¹æ¡ �æÃ �¤Çoµ« �¨¹ÁÕo u³ËÀÙÁie¾ ièÁ¢ é¹¨Ò¡ 298 K e»�¹ 1000 K

¨§¤íÒ¹Ç³ËÒ¤ÇÒÁÃ �o¹¢o§» i¡ iÃ iÂÒe¤ÁÕµ �oä»¹Õé ³ 298 K2H2S(g) + 3O2(g) ↔ 2H2O(l) + 2SO2(g)


EX 1: eo¹·ÒÅ» �·Õèe»ÅÕèÂ¹æ»Å§ eÁèoou³ËÀÙÁiäÁ�¤§·Õè

¨§¤íÒ¹Ç³ËÒ¤ÇÒÁÃ �o¹·ÕèãË�æ¡�æÃ �¤Çoµ« � íÒ¹Ç¹ 1 mol e¾ èoãË�ou³ËÀÙÁ ie¾ ièÁ¢ é¹¨Ò¡ 298 K e»�¹ 1000 K

µaÇæ»Ã ¤�Òa 104.35

b 6.07x10-3

c 3.4x10-4

d -1070

¡íÒË¹´ãË�

( ) ( )

( )

2

1

2

1

2 0.52 1

10002

298

2 2

-1

22

1000 298 1000 2982

1 1 2 1000 2981000 298

45.37 kJ mol

T

T

T

T

H H H a bT cT dT dT

b cH aT T d TTba

c d

H

− −

=

=

− = Δ = + + +⎡ ⎤⎣ ⎦

⎡ ⎤Δ = + − +⎢ ⎥⎣ ⎦

= − + −

⎛ ⎞− − + −⎜ ⎟⎝ ⎠

Δ =

∫

Cp = a + bT + cT-2 + dT-0.5

2 2

1 1

p

H T

pH T

dH C dT

dH C dT

=

=∫ ∫

µ �o§ãË �¤ÇÒÁÃ �o¹e»�¹»ÃiÁÒ³ 45.37 kJ ¨§ä·íÒãË �æÃ�¤Çoµ«�íÒ¹Ç¹ 1 oÁÅ ÁÕo u³ËÀÙÁ ie¾ ièÁ¨Ò¡ 298 K e»�¹ 1000 K

Cp = dH/dT


EX 2: eo¹·ÒÅ» �·Õèe»ÅÕèÂ¹æ»Å§ ³ ou³ÀÙÁi¤§·Õè

¨§¤íÒ¹Ç³ËÒ¤ÇÒÁÃ �o¹¢o§» i¡ iÃ iÂÒe¤ÁÕµ �oä»¹Õé ³ 298 K2H2S(g) + 3O2(g) ↔ 2H2O(l) + 2SO2(g)

ΔHr = Σ(ΔHfo)products � Σ(ΔHf

o)reactants Compound ΔHof

(kJ/mol)

H2S (g) -20.6

O2 (g) 0

H2O (l) -285.8

SO2 (g) -296.8

¨Ò¡µÒÃÒ§

[ ] [ ]2( 285.8) 2( 296.8) 2( 20.6) 3(0)

1124 kJrHΔ = − + − − − +

= −

³ o u³ËÀÙÁi 298 K » i¡ iÃiÂÒe¤ÁÕã¹Ãaºº¢�Ò§µ�¹äÁÕeo ç¹·ÒÅ» �Å´Å§ (ËÃo¤ÒÂ¤ÇÒÁÃ �o¹) e·�Ò¡ aº 1124 kJ


ΔH = �+�

e¤Ãèo§ËÁÒÂ¢o§ ΔH

ระบบจะดดความรอนเขาไปในตวมน ซงเรยกปฏกรยาหรอการเปลยนแปลงแบบนวา Endothermic reaction/transformation

ΔH = �−� ระบบจะคายความรอนใหกบสงแวดลอม ซงเรยกปฏกรยาหรอการเปลยนแปลงแบบนวา Exothermic reaction/transformation

Lecture 9 - Thermodynamics III 1


Constant Pressure Heat Capacity (Cp)Enthalpy (H)Entropy (S)Gibbs Free Energy (G)Molar Volume (V)

e¹ �¹e©¾Òa·Õèä¹íÒÁÒãª�¡ aº¸Ã³ÕÇ i·ÂÒ


ΔH ·Õèe»ÅÕèÂ¹æ»Å§ä»¢o§»¯ i¡ iÃ iÂÒ·Õèou³ËÀÙÁioè¹æ

eª �¹ oÂÒ¡·ÃÒºÇ �Ò äÁÕ¾Å a§§Ò¹¤ÇÒÁÃ �o¹¶�ÒÂe·e·�Òã´ ¶�Ò»¯ i¡iÃ iÂÒe¤ÁÕµ�oä»¹Õé « è§e¡i´·Õèou³ËÀÙÁ i 1000 K?

ã¹¡Ã³Õeª �¹¹Õé äãª �µÒÃÒ§¤ �Òe·oÃ �oÁä´¹ÒÁ i¡Ê�e¾ÕÂ§oÂ �Ò§e ÕÂÇäÁ �ä � e¾ÃÒaµÒÃÒ§äÁÕe©¾Òa¤�Ò ΔHo

f ³ 298 K e·�Ò¹aé¹ äµ�o§ãª � heat capacity (Cp) ÁÒe¡ÕèÂÇ¢ �o§

Si(s) + O2(g) ↔ SiO2(s)


µaÇæ»Ã SiO2 Si O2

31.778 48.318

-6.91x10-4

4.99x105

d -1070 -178.6 -420.7

ΔHfo (kJ/mol) -910.9 0 0

5.39x10-4

-1.47x105

a 104.35

b 6.07x10-3

c 3.4x10-4

¢�oÁÙÅ·Õè¡íÒË¹´ãË�

− −= + + +2 0.5PC a bT cT dT


Çi Õ·íÒ: ¢aé¹·Õè 1 ¤íÒ¹Ç³ËÒ¤ �Ò ΔHro

ΔHro = Σ(ΔHf

o)products � Σ(ΔHfo)reactants

⎡ ⎤ ⎡ ⎤Δ = Δ − Δ + Δ⎣ ⎦ ⎣ ⎦= − − += −

o o o o

2 2r f ,SiO f ,Si f ,Oproduct reactantH H H H

( 910.9) (0 0)

910.9 kJ

¤�Ò·Õèä �¤oeo ç¹·ÒÅ»�¢o§» i¡ iÃiÂÒ ³ ÊÀÒÇaÁÒµÃ°Ò¹ (T=298 K, P=1 atm)


Çi Õ·íÒ: ¢aé¹·Õè 2 ¤íÒ¹Ç³ËÒ¤ �Ò ΔCP

− −Δ = Δ + Δ + Δ + Δ2 0.5PC a bT cT dT

( ) ( ) ( )Δ = −∑ ∑P P Pr product reactantC C C

[ ] [ ]

( )( )

[ ] ( ) ( )[ ]

− − − −

−

Δ = − + =

⎡ ⎤Δ = × − × + − × = ×⎡ ⎤⎣ ⎦ ⎣ ⎦

⎡ ⎤Δ = × − − × + × = − ×⎡ ⎤⎣ ⎦ ⎣ ⎦Δ = − − − + − = −

prod reac

3 4 4 3

prod reac

4 5 5 5

prod reac

prod reac

a 104.35 31.778 48.318 24.254

b 6.07 10 5.39 10 6.91 10 6.222 10

c 3.40 10 1.47 10 4.99 10 3.52 10

d 1070 178.6 420.7 470.7

โดยคาสมประสทธตางๆ คานวณไดดงน


Çi Õ·íÒ: ¢aé¹·Õè 3 ¤íÒ¹Ç³ËÒ¤ �Ò ΔHr( )

( )Δ

Δ

Δ = Δ

Δ = Δ∫ ∫T 2 2

T 1 1

P

H T

PH T

d H C dT

d H C dTΔ = Δ + Δ∫

2

2 1

1

T

T T PT

H H C dT

− −Δ = Δ + Δ + Δ + Δ2 0.5PC a bT cT dT

( ) ( )

( )

=

==

=− −

==

=

= Δ + Δ

= Δ + Δ + Δ + Δ + Δ⎡ ⎤⎣ ⎦

Δ Δ⎡ ⎤= Δ + Δ + − + Δ⎢ ⎥⎣ ⎦Δ⎧ ⎫Δ − + −⎪ ⎪⎪ ⎪= Δ + ⎨ ⎬

⎛ ⎞⎪ ⎪−Δ − + Δ −⎜ ⎟⎪ ⎪⎝ ⎠⎩ ⎭

∫

∫

T 1000

r ,T 298 PT 298

T 1000o 2 0.5r

T 298

T 1000o 2r

T 298

2 2

or

H C dT

H a bT cT dT dT

b cH aT T 2 d T

2 Tb

a 1000 298 1000 2982H

1 1c 2 d 1000 298

1000 298

Ë¹ �ÇÂ¢o§ CP ¤ o J mol-1 K-1

Ë¹ �ÇÂ¢o§ ΔCP ¤o J K-1

Ë¹ �ÇÂ¢o§ ∫ΔCP ¤o J

=Δ r ,T 1000H


Çi Õ·íÒ: ¢aé¹·Õè 3 ¤íÒ¹Ç³ËÒ¤ �Ò ΔHr (µ�o)( ) ( )

( )=

Δ⎧ ⎫Δ − + −⎪ ⎪⎪ ⎪Δ = Δ + ⎨ ⎬⎛ ⎞⎪ ⎪−Δ − + Δ −⎜ ⎟⎪ ⎪⎝ ⎠⎩ ⎭

= − += − += −

2 2

T 1000 or r

ba 1000 298 1000 298

2H H1 1

c 2 d 1000 2981000 298

910.9 kJ 5513.232 J

910.9 kJ 5.51 kJ

905.39 kJ

a§¹aé¹ » i¡ iÃiÂÒ¡ÒÃe¡ i´æÃ�¤Çoµ«�·Õè 1000 K (1.0 atm) äÁÕ¡ÒÃ¤ÒÂ¾Å a§§Ò¹oo¡ÁÒ 905.4 kJ (eo ç¹·ÒÅ» �Å´Å§)

−

Δ =

Δ = ×

Δ = − ×

Δ = −

3

5

a 24.254

b 6.222 10

c 3.52 10

d 470.7


Entropy, S

¡ÒÃe»ÅÕèÂ¹æ»Å§ã´æ ·ÕèÁÕ¡ÒÃ¶ �ÒÂe·¤ÇÒÁÃ �o¹e¢ �Ò-oo¡¨Ò¡Ãaºº äÁÕ¡ÒÃe»ÅÕèÂ¹æ»Å§¢o§eo ç¹o·Ã» � �ÇÂeÊÁoeª�¹ ¹éíÒe»ÅÕèÂ¹Ê¶Ò¹a » i¡ iÃ iÂÒe¤ÁÕ¢o§æÁ¡ÁÒ¡ aºæÃ � ¡ÒÃ¼u¾ a§·íÒÅÒÂ¢o§æÃ � ÏÅÏ

⎧= = ⎨

⎩

P

V

C dT T for constant pressuredQdS

C dT T for constant volumeT Ê �Ç¹ãË�äãª �ÊÁ¡ÒÃ·ÕèÁÕ Cp


¡. ¡ÒÃe»ÅÕèÂ¹æ»Å§eo ç¹o·Ã» �eÁèoÁÕ¡ÒÃe»ÅÕèÂ¹Ê¶Ò¹a

¹éíÒe»ÅÕèÂ¹Ê¶Ò¹a¨Ò¡¹éíÒ¡ÅÒÂe»�¹äo (·Õè¤ÇÒÁ´ a¹ P = 1.0 atm)äÁÕeoç¹o·Ã»�e»ÅÕèÂ¹ä»e·�Òã´? H2O(l) ↔ H2O(g)

Δ= =

Δ + ×Δ = =

= +

r

3r

r

dQ d( H )dS

T TH 40.67 10 J

ST 373.15 K109 J/K

e¹ èo§¨Ò¡¹éíÒ¡ÅÒÂe»�¹äo·Õèou³ËÀÙÁi¤§·Õè (373.15 K) a§¹ aé¹ ¢�o¹ÕéäÁ�¨íÒe»�¹µ�o§oi¹· ie¡Ãµ e¾ÕÂ§æ¤ �·ÃÒº¤ÇÒÁÃ �o¹æ½§¢o§¡ÒÃ¡ÅÒÂe»�¹äo¢o§¹éíÒ (¾Å a§§Ò¹¤ÇÒÁÃ�o¹·Õè¹éíÒ´Ù e¢�Òä»æÅ �ÇÃaeËÂ¡ÅÒÂe»�¹äo) «è§ÁÕ¤ �Òe· �Ò¡ aº 40.67 kJ/mol

¹aè¹¤o eÁèo¹éíÒä �Ãaº¤ÇÒÁÃ�o¹¨¹¡ÅÒÂe» �¹äo (·Õèo u³ËÀÙÁi¤§·Õè 373.15 K, 1.0 atm) ÃaººäÁÕeo ç¹o·Ã» �e¾ ièÁ¢é¹ 109 J/K ¹aè¹

¤o ÃaººäÁÕ¤ÇÒÁäÃ�ÃaeºÕÂºe¾ ièÁ¢é¹


¢. ¡ÒÃe»ÅÕèÂ¹æ»Å§eo ç¹o·Ã»�ã¹¡Ã³Õ·Õèo u³ËÀÙÁie¾ièÁ¢é¹ æµ�äÁ�e¡ i » i¡ iÃiÂÒe¤ÁÕ

¨§¤íÒ¹Ç³ËÒeoç¹o·Ã»�¢o§æÃ �¤Çoµ« � 1.0 mol eÁ èoä �Ã aº¤ÇÒÁÃ �o¹¨¹ÁÕou³ËÀÙÁ ie¾ ièÁe»�¹e»�¹ 1000 K

ãª�¹iÂÒÁ¢o§eo ç¹o·Ã» � (dS = CpdT/T)ãª�µÒÃÒ§ËÒ¤ �Ò So ³ o u³ËÀÙÁi·ÕèeÃÒ·ÃÒº

Cp = a + bT + cT-2 + dT-0.5T2

T 1

2

2 1

1

S T2P P

S T1

TP

T TT

C CdS dT dS dT

T T

CS S dT

T

= → → =

− =

∫ ∫

∫

L

เลอก T1 = 298 K, So = 41.8 J/Kให T2 = 1000 K, แลวคานวณหา ST2


Ç i¸Õ·íÒ: (µ �o)

µaÇæ»Ã ¤�Òa 104.35

b 6.07x10-3

c 3.4x10-4

d -1070

¡íÒË¹´ãË�

Cp = a + bT + cT-2 + dT-0.5

( ) ( )

2

2 1

1

2

TP

T TT

1000 2 0.5

T298

10003 1.5

1000K298

1000

2298

2 2

CS S dT

T

[a bT cT dT ]S 41.8 dT

T

aS 41.8 b cT dT dT

T

c 2d41.8 a ln T bT

2T T41.8 a ln 1000 ln 298 b 1000 298

c 1 1 1 12d

2 1000 298 1000 298

− −

− −

− =

+ + +− =

⎡ ⎤= + + + +⎢ ⎥⎣ ⎦

⎡ ⎤= + + − −⎢ ⎥⎣ ⎦= + − + −

⎛⎛ ⎞− − − −⎜ ⎟⎝ ⎠ ⎝

∫

∫

∫

41.8 74.3 116.1 J/K

⎞⎜ ⎟

⎠= + = Sqtz, 1000K = 116.1 J/K


¤. ¡ÒÃe»ÅÕèÂ¹æ»Å§eo ç¹o·Ã» �ã¹¡Ã³Õ·Õèe»�¹»¯ i¡iÃ iÂÒe¤ÁÕ

µ�o§¡ÒÃ·ÃÒº¤ �Òeoç¹o·Ã»�·Õèe»ÅÕèÂ¹ä»¢o§»¯ i¡iÃ iÂÒ (ΔSr) µ�oä»¹Õé ³ ou³ËÀÙÁ i 298 K æÅa 1000 K (·Õè¤ÇÒÁ´ a¹ P = 1.0 atm)

¡Ã³Õeª�¹¹Õé ä¤Å �ÒÂ¡ aº¡Ã³Õ¢o§eo ç¹·ÒÅ» �·Õèe¾ iè§ä¤íÒ¹Ç³ä» «è§¡ �o¹o è¹µ�o§ãª�¤�Ò¨Ò¡µÒÃÒ§e·oÃ�oÁä´¹ÒÁ i¡Ê �ËÒ¤�Ò¢o§

ΔSro (·ÕèÊÀÒÇaÁÒµÃ°Ò¹) eÊÕÂ¡ �o¹ æÅ �Ç¨§ãª�¹iÂÒÁ¢o§eo ç¹

o·Ã» �e¾ èoËÒ¤�Ò ΔSr ·Õèo u³ËÀÙÁiÊÙ§¢é¹µ�oä»

Si(s) + O2(g) ↔ SiO2(s)


µaÇæ»Ã SiO2 Si O2

31.778 48.318

-6.91x10-4

4.99x105

d -1070 -178.6 -420.7

So (J/mol-K) 41.8 18.8 205.1

5.39x10-4

-1.47x105

a 104.35

b 6.07x10-3

c 3.4x10-4

¢�oÁÙÅ·Õè¡íÒË¹´ãË�

− −= + + +2 0.5PC a bT cT dT


Çi Õ·íÒ: ¢aé¹·Õè 1 ¤íÒ¹Ç³ËÒ¤ �Ò ΔSo

ΔSro = Σ(So)products � Σ(So)reactants

2 2r SiO Si Oproduct reactantS S S S

(41.8) (18.8 205.1)

182.1 J/K

⎡ ⎤ ⎡ ⎤Δ = − +⎣ ⎦ ⎣ ⎦= − += −

o o o o

¤�Ò·Õèä �¤oeo ç¹o·Ã»�¢o§» i¡ iÃiÂÒ ³ ÊÀÒÇaÁÒµÃ°Ò¹ (T=298 K, P=1 atm)


Çi Õ·íÒ: ¢aé¹·Õè 2 ¤íÒ¹Ç³ËÒ¤ �Ò ΔCP

− −Δ = Δ + Δ + Δ + Δ2 0.5PC a bT cT dT

( ) ( ) ( )Δ = −∑ ∑P P Pr product reactantC C C

[ ] [ ]

( )( )

[ ] ( ) ( )[ ]

− − − −

−

Δ = − + =

⎡ ⎤Δ = × − × + − × = ×⎡ ⎤⎣ ⎦ ⎣ ⎦

⎡ ⎤Δ = × − − × + × = − ×⎡ ⎤⎣ ⎦ ⎣ ⎦Δ = − − − + − = −

prod reac

3 4 4 3

prod reac

4 5 5 5

prod reac

prod reac

a 104.35 31.778 48.318 24.254

b 6.07 10 5.39 10 6.91 10 6.222 10

c 3.40 10 1.47 10 4.99 10 3.52 10

d 1070 178.6 420.7 470.7

โดยคาสมประสทธตางๆ คานวณไดดงน


Çi Õ·íÒ: ¢aé¹·Õè 3 ¤íÒ¹Ç³ËÒ¤ �Ò ΔSr

( )

( )Δ

Δ

ΔΔ =

ΔΔ =∫ ∫

T 2 2

T 1 1

P

S TP

S T

Cd S dT

T

Cd S dT

T

ΔΔ = Δ + ∫

2

2 1

1

TP

T TT

CS S dT

T− −Δ = Δ + Δ + Δ + Δ2 0.5

PC a bT cT dT

( ) ( )

=

= ==

− −=

==

=

ΔΔ = Δ +

Δ + Δ + Δ + Δ⎡ ⎤⎣ ⎦= Δ +

Δ Δ⎡ ⎤= Δ + Δ + Δ − −⎢ ⎥⎣ ⎦Δ − + Δ −

= Δ + Δ ⎛ ⎞⎛ ⎞− − − Δ −⎜ ⎟ ⎜ ⎟⎝ ⎠ ⎝ ⎠

∫

∫

T 1000P

r ,T 1000 r ,T 298T 298

2 0.5T 1000or

T 298

T 1000or 2

T 298

or

2 2

CS S dT

T

a bT cT dTS dT

T

c 2 dS a ln T bT

2T T

a ln 1000 ln 298 b 1000 298

S c 1 1 1 12 d

2 1000 298 1000 298

⎧ ⎫⎪ ⎪⎨ ⎬⎪ ⎪⎩ ⎭


Çi Õ·íÒ: ¢aé¹·Õè 3 ¤íÒ¹Ç³ËÒ¤ �Ò ΔHr (µ�o)

( ) ( )=

Δ − + Δ −⎧ ⎫⎪ ⎪Δ = Δ + Δ⎨ ⎬⎛ ⎞⎛ ⎞− − − Δ −⎜ ⎟ ⎜ ⎟⎪ ⎪⎝ ⎠ ⎝ ⎠⎩ ⎭

= − += −

T 1000 or r

2 2

a ln 1000 ln 298 b 1000 298

S S c 1 1 1 12 d

2 1000 298 1000 298182.1 J/K 7.16 J/K

174.94 kJ

a§¹aé¹ » i¡ iÃiÂÒ¡ÒÃe¡ i´æÃ�¤Çoµ«�·Õè 1000 K (1.0 atm) äÁÕeo ç¹o·Ã» �Å´Å§ 174.94 J/K « è§o´ÂÃÇÁæÅ �Ç·Õè 1000 K Â a§¤§ÁÕeo ç¹o·Ã» �ÊÙ§¡Ç�Ò·Õè 298 K

−

Δ =

Δ = ×

Δ = − ×

Δ = −

3

5

a 24.254

b 6.222 10

c 3.52 10

d 470.7


eo ç¹·ÒÅ» �·Õèe»ÅÕèÂ¹æ»Å§¢o§»¯ i¡iÃ iÂÒ äe»�¹µ aÇº �§ºo¡Ç �Ò eÁèoe¡i´» i¡iÃ iÂÒæÅ �Ç ÃaººäÁÕ¾Å a§§Ò¹e¾ ièÁ¢ é¹ËÃoÅ´Å§ถาระบบคายความรอน (Exothermic) ระบบจะมพลงงานลดลง

ถาระบบดดความรอน (Endothermic) ระบบจะมพลงงานเพมขน

æµ�¡ÒÃe»ÅÕèÂ¹æ»Å§eo ç¹·ÒÅ»� ¡çÂa§äÁ�ÊÒÁÒÃ¶¹íÒÁÒº �§ºo¡Ç�Ò » i¡ iÃiÂÒa§¡Å�ÒÇäe¡ i´¢é¹ä �ËÃoäÁ� e¾ÃÒa¡ÒÃe»ÅÕèÂ¹æ»Å§Ë¹è§æ äÁ�ä �e¡ÕèÂÇ¢ �o§

¡ aº¾Åa§§Ò¹·Õèe¢�Ò-oo¡¨Ò¡Ãaººe¾ÕÂ§oÂ�Ò§e ÕÂÇ Â a§¢ é¹oÂÙ�¡ aº¡ÒÃe»ÅÕèÂ¹æ»Å§eo ç¹o·Ã»�o Õ¡ �ÇÂ ¨ §ä �ÁÕ¡ÒÃ¤i´¤�¹¿�§¡ �ªa¹º�§Ê¶Ò¹aµaÇãËÁ�¢é¹ÁÒeÃÕÂ¡Ç �Ò �¾Åa§§Ò¹oiÊÃa (G)�


Gibbs Free Energy, G

¾Åa§§Ò¹oiÊÃa (G) ¤ o¾Åa§§Ò¹« è§ÊaÊÁoÂÙ�ã¹Ãaºº ·Õè¾Ã �oÁäe¡ i´» i¡ iÃ iÂÒËÃ o¡ÒÃe»ÅÕèÂ¹æ»Å§ (tendency to react)

¹íÒÁÒãª�·íÒ¹ÒÂÇ �Ò » i¡ iÃ iÂÒËÃ o¡ÒÃe»ÅÕèÂ¹æ»Å§´ a§¡Å�ÒÇ äe¡ i ¢ é¹eo§ä´ �ËÃ oäÁ� (spontaneous)¹íÒÁÒãª�ã¹¡ÒÃ¤íÒ¹Ç³ËÒ¤ �ÒÊÁúÅe¤ÁÕ (K)

G H TS= −นยาม


Gibbs Free Energy Change (ΔG)

³ ÊÀÒÇao è¹æ ·ÕèäÁ�ãª�ÊÀÒÇaÁÒµÃ°Ò¹ ¡ÒÃe»ÅÕèÂ¹æ»Å§¢o§¾Å a§§Ò¹oiÊÃa (ΔG) ËÒä �¨Ò¡¤ÇÒÁÊ aÁ¾ a¹¸ �

ΔGro = Σ(ΔGf

o)products � Σ(ΔGfo)reactants

¡ÒÃe»ÅÕèÂ¹æ»Å§¢o§¾Åa§§Ò¹oiÊÃa (ΔG) ¢o§ chemical reaction ËÃ o transformation ³ ÊÀÒÇaÁÒµÃ°Ò¹ ¤íÒ¹Ç³ä �¨Ò¡ÊÙµÃµ�oä»¹Õé

ΔG = ΔH- TΔS


¤ÇÒÁÊaÁ¾a¹¸ �ÃaËÇ �Ò§¾Å a§§Ò¹oiÊÃa¡aº¤ �Ò¤§·ÕèÊÁ uÅ (K)

c d

a b

[C] [D]Q

[A] [B]′ =

[ ]oG G RT ln Q′Δ = Δ +

oG RTK e−Δ=

Law of Mass Action:

ÊíÒËÃaº» i¡ iÃiÂÒe¤ÁÕ aA + bB = cC + dD

¤ÇÒÁÊaÁ¾a¹ �ÃaËÇ�Ò§ ΔG æÅa Q′ ¤o

³ ÊÀÒÇaÊÁ uÅ ΔG →0, Q′→K

[ ]o

o G0 G RT ln K lnK

RTΔ

= Δ + → → = −LL


» i¡ iÃiÂÒ¡ÒÃæµ¡µ aÇ¢o§¹éíÒ ³ 298 K

H2O(l) = H+(aq) + OH-

(aq)

ΔGro = Σ(ΔGf

o)products � Σ(ΔGfo)reactants

·Õèo u³ËÀÙÁi 298 K ¾Åa§§Ò¹oiÊÃa¢o§» i¡ iÃiÂÒ¡ÒÃæµ¡µ aÇe·�Ò¡ aº

[ ] [ ]2r f ,H Of ,H f ,OH reactantproduct

G G G G

0 ( 157.2) 237.1

79.9 kJ

+ −⎡ ⎤ ⎡ ⎤Δ = Δ + Δ − Δ⎣ ⎦⎣ ⎦= + − − −= +

o o o o

¤�Ò¢o§ ΔG e»�¹ �ºÇ¡� æÊ´§Ç�Ò» i¡ iÃiÂÒe¤ÁÕ¹Õé äÁ�¤ÇÃäe¡ i´¢é¹ä �eo§


» i¡ iÃiÂÒ¡ÒÃæµ¡µ aÇ¢o§¹éíÒ ³ 298 K

oo

G RTGK exp e

RT−ΔΔ⎡ ⎤= − =⎢ ⎥⎣ ⎦

H2O(l) = H+(aq) + OH-

(aq)

·Õèo u³ËÀÙÁi 298 K ¤�Ò¤§·ÕèÊÁ uÅ¤íÒ¹Ç³ä �¨Ò¡

332.25

15

14

79.9 10K exp e

8.3143 298

9.9 10

10

−

−

−

×⎡ ⎤= − =⎢ ⎥×⎣ ⎦= ×

≈«è§·Õèe¤ÂeÃÕÂ¹ÁÒã¹Ãa aºÁa ÂÁ

K = KW= [H+][OH-] = 10-14


Molar Volume, VMolar Volume ËÁÒÂ¶§»Ã iÁÒµÃ¢o§ÊÊÒÃ (cm3 ËÃo m3) íÒ¹Ç¹ 1 moleª�¹ æ¡�Êã¹ou´Á¤µi íÒ¹Ç¹ 1 oÁÅ (·Õè 298 K, 1.0 atm) ÁÕ¤�Òe·�Ò¡aº 24.5 ÅiµÃ

eª�¹ æÃ�æ¤Åä«µ � íÒ¹Ç¹ 1 oÁÅ (·Õè 298 K, 1.0 atm) ÁÕ»ÃiÁÒµÃe·�Ò¡aº 36.93 cm3

¹íÒÁÒãª �·íÒ¹ÒÂ¡ÒÃe¡i »¯ i¡iÃ iÂÒ/¡ÒÃe»ÅÕèÂ¹æ»Å§·ÕèÁÕ»Ã iÁÒµÃäÁ �¤§·Õè (« è§äÁÕ¼Åµ�o¤ÇÒÁ´ a¹¢o§Ãaºº)

ΔVr = Σ(V)products � Σ(V)reactantso´ÂÁÒ¡æÅ�Ç molar volume ¢o§ �¢o§æ¢ç§� ä¤§·Õè äÁ�e»ÅÕèÂ¹æ»Å§¡ aº T, P ÁÒ¡e·�ÒäËÃ�


» i¡ iÃiÂÒ¢o§ooÅiÇÕ¹¡ aº¤Çoµ« �

Mg2SiO4 + SiO2 → 2MgSiO3

¨§¤íÒ¹Ç³ËÒ»Ã iÁÒµÃ·Õèe»ÅÕèÂ¹æ»Å§ÊíÒËÃaº» i¡ iÃiÂÒ¢o§æÃ �¢�Ò§µ�¹

( )[ ] [ ]

enstatite forsterite qtzproduct reactant

3

V 2 V V V

2(43.79) 31.28 22.69

33.61 cm

⎡ ⎤Δ = − +⎡ ⎤⎣ ⎦ ⎣ ⎦= − +

= + ¤�Ò¢o§ ΔV e» �¹ �ºÇ¡� æÊ´§Ç �Ò» i¡ iÃiÂÒ¹Õé ·íÒãË�»ÃiÁÒµÃe¾ ièÁ¢é¹ a§¹aé¹ ¹�Òäe¡ i´ã¹ÊÀÒÇaæÇ´Å �oÁ·ÕèÁÕ �¤ÇÒÁ a¹µèíÒ�

forsterite qtz enstatite

ΔVr = Σ(V)products � Σ(V)reactants

Lecture 10 - Thermodynamics IV 1


Free Energy Change with varying T & PGeothermometry & GeobarometryEquilibrium ConstantsChemical Potential & Fugacity - Introduction


¡ÃaºÇ¹¡ÒÃ·Õè T & P äÁ�¤§·Õèo´Â»¡µiæÅ �Ç ¡ÃaºÇ¹¡ÒÃ·Ò§¸Ã³ÕÇ i·ÂÒÊ �Ç¹ãË�äÁÕ¡ÒÃe»ÅÕèÂ¹æ»Å§·aé§ou³ËÀÙÁ iæÅa¤ÇÒÁ´ a¹ä»¾Ã �oÁæ ¡a¹ eª �¹ »¯ i¡iÃ iÂÒ¡ÒÃµ¡¼Å ¡¢o§æÁ¡ÁÒã¹¢³a·Õèe¤Å èo¹µaÇ¢ é¹ÁÒã¡Å �¼iÇoÅ¡

¡ÒÃ¤íÒ¹Ç³ËÒ¤ �Ò¢o§ ΔGT,P ¢o§»¯ i¡iÃ iÂÒ äµ�o§ãª �¤�Ò ΔHof,

ΔSo, ΔCP, æÅa ΔV ³ ÊÀÒÇaÁÒµÃ°Ò¹æÅ �Ç¤íÒ¹Ç³ (oi¹·ie¡Ãµ) ä»ÊÙ�ou³ËÀÙÁ iæÅa¤ÇÒÁ´ a¹·Õèµ�o§¡ÒÃ·ÃÒº o´Âãª �ÊÁ¡ÒÃ

( )atm atm

T Tp

T ,P 298,P p 298,P atm298 298

CG H C dT T S dT V P P

T

Δ⎡ ⎤ ⎡ ⎤Δ = Δ + Δ − Δ + + Δ −⎢ ⎥ ⎢ ⎥

⎣ ⎦ ⎣ ⎦∫ ∫o o

ΔGT,Patm


¡ÒÃ¹íÒÊÁ¡ÒÃ ΔGT,P ä»»ÃaÂu¡µ �ãª �

ãª�¤íÒ¹Ç³ËÒ �o u³ËÀÙÁiæÅa¤ÇÒÁ´ a¹� ¢o§Ëi¹« è§¾ºÇ �ÒÁÕæÃ �Êo§ª¹ i ¢ é¹ä»oÂÙ� �ÇÂ¡ a¹oÂ �Ò§ÊÁúÅ (ΔGT,P = 0)

¡Å�ÒÇ¤o eÃÒãª � mineral assemblages e»�¹µ aÇº �§ªÕé T æÅa P ·ÕèÁa¹e¡ i o´Â¡ÒÃ¹íÒ¤ÇÒÁÃÙ�·Ò§e·oÃ �oÁä´¹ÒÁi¡Ê�ÁÒãª� « è§e·¤¹ i¤¹ÕéeÃÒeÃÕÂ¡Ç �Ò Geothermometry (T) æÅa Geobarometry (P)


Geothermometry & Geobarometry

( )atm atm

T Tp

T ,P 298,P p 298,P atm298 298


T

Δ⎡ ⎤ ⎡ ⎤Δ = Δ + Δ − Δ + + Δ −⎢ ⎥ ⎢ ⎥

⎣ ⎦ ⎣ ⎦∫ ∫

atm atm

atm

298,P 298,P

p ,298,P

H , S ,

C , V

Δ Δ

Δ Δ → คานวณไดจากคาในตาราง

Patm = 1.01325×105 N/m2 (1 atm)

³ ÊÀÒÇaÊÁ uÅ ¡íÒË¹´ãË� ΔGT,P = 0 æÅ �Çæ¡ �ÊÁ¡ÒÃËÒ¤ �Ò¢o§ T ËÃo P oo¡ÁÒ


¢�o¤ÇÃÃaÇ a§ã¹¡ÒÃ¤íÒ¹Ç³ (eÃèo§Ë¹�ÇÂ)

ΔG æÅa ΔH ¤ÇÃe»ÅÕèÂ¹Ë¹ �ÇÂãË�e» �¹ J (æ·¹·Õèäe» �¹ kJ)

ΔS æÅa S ÁÕË¹�ÇÂe» �¹ J/K ËÃo J/mol-K

ΔCp æÅa Cp ÁÕË¹�ÇÂe» �¹ J/K ËÃo J/mol-K

P ÁÕË¹�ÇÂe» �¹ N/m2 æÅa T ÁÕË¹�ÇÂe» �¹ Kelvin

1 atm = 1.01325 x 105 N/m2

T (K) = 273.15 + T(oC)R = 8.3143 J/mol-KV ÁÕË¹ �ÇÂe»�¹ m3/mol


µ aÇoÂ�Ò§: ¡ÒÃº �Ò¹ #3 ¢�o 6

µ�o§¡ÒÃ·ÃÒºou³ËÀÙÁ i·ÕèæÃ � kyanite æÅa andalusite oÂÙ� �ÇÂ¡ a¹oÂ �Ò§ÊÁ uÅ ³ ¤ÇÒÁ´ a¹ 1 atm

( )atm atm

T Tp

T ,P 298,P p 298,P atm298 298


T

Δ⎡ ⎤ ⎡ ⎤Δ = Δ + Δ − Δ + + Δ −⎢ ⎥ ⎢ ⎥

⎣ ⎦ ⎣ ⎦∫ ∫o o

เทากบศนย(สมดล)

เปดตารางแลวคานวณ

เปดตารางแลวคานวณ

เทากบศนยความดนคงท

æ·¹¤ �ÒµaÇeÅ¢¨Ò¡µÒÃÒ§ (¡ÒÃº �Ò¹ #3) Å§ä» ää �x x

pp

298 298

C0 4285.6 C dT x 9.2 dT 0

T

Δ⎡ ⎤ ⎡ ⎤= − + Δ − − + +⎢ ⎥ ⎢ ⎥⎣ ⎦ ⎣ ⎦

∫ ∫æ¡ �ÊÁ¡ÒÃ ( �ÇÂ¤oÁÏ)

x = 463.15 K


¤ÇÒÁÊaÁ¾a¹¸ �ÃaËÇ �Ò§¾Å a§§Ò¹oiÊÃa¡aº¤ �Ò¤§·ÕèÊÁ uÅ (K)

c d

a b

[C] [D]Q

[A] [B]′ =

[ ]oG G RT ln Q′Δ = Δ +

Law of Mass Action:

ÊíÒËÃ aº»¯ i¡ iÃ iÂÒe¤ÁÕ aA + bB = cC + dD

¤ÇÒÁÊaÁ¾a¹¸ �ÃaËÇ �Ò§ ΔG æÅa Q′ ¤ o

³ ÊÀÒÇaÊÁ uÅ ΔG →0, Q′→K

[ ]o

o G0 G RT ln K lnK

RTΔ

= Δ + → → = −LLo

oG RTG

K exp eRT

−ΔΔ⎡ ⎤= − =⎢ ⎥⎣ ⎦


oT2 r

T 1 2 1

K H 1 1ln

K R T T

⎡ ⎤ ⎡ ⎤Δ≈ − −⎢ ⎥ ⎢ ⎥

⎣ ⎦ ⎣ ⎦

¤ �Ò K e»ÅÕèÂ¹ä» eÁèoo u³ËÀÙÁ ie»ÅÕèÂ¹

µaÇoÂ �Ò§eª�¹ eÁèo·ÃÒº¤ �Ò¤§·ÕèÊÁ uÅ ³ o u³ËÀÙÁi T1 = 298 K ÊÒÁÒÃ¶¤íÒ¹Ç³ËÒ¤ �Ò¤§·ÕèÊÁ uÅ ³ o u³ËÀÙÁio è¹æ ä � o´ÂÊÁÁuµãË�¤ �Ò ΔHr

o äÁ�e»ÅÕèÂ¹æ»Å§ÁÒ¡¹ a¡ã¹ª�Ç§o u³ËÀÙÁi·Õèµ�o§¡ÒÃËÒ¤íÒ¹Ç³


[ ]P22 1

P1

K Vln P P

K RT

⎡ ⎤ Δ≈ − −⎢ ⎥

⎣ ⎦

¤ �Ò K e»ÅÕèÂ¹ä» eÁèo¤ÇÒÁ´ a¹e»ÅÕèÂ¹

µaÇoÂ �Ò§eª�¹ eÁèo·ÃÒº¤ �Ò¤§·ÕèÊÁ uÅ ³ ¤ÇÒÁ a¹ P1 = 1.0 atm(1.01325x105 N/m2) ÊÒÁÒÃ¶¤íÒ¹Ç³ËÒ¤ �Ò¤§·ÕèÊÁ uÅ ³ ¤ÇÒÁ a¹o è¹æ ä � o´ÂÊÁÁuµiãË�¤ �Ò ΔV äÁ�e»ÅÕèÂ¹æ»Å§ÁÒ¡¹ a¡ ã¹ª�Ç§¤ÇÒÁ a¹·Õèµ�o§¡ÒÃ¤íÒ¹Ç³


Chemical Potential

¡ÒÃ¤íÒ¹Ç³¤�Ò·Ò§e·oÃ�oÁä´¹ÒÁ i¡Ê �·ÕèeÃÕÂ¹ä» e» �¹¡ÒÃ¤�Ò·Õèãª�ä �ÊíÒËÃaºÊÒÃºÃiÊu·¸ iì äÁ�ÁÕÊ iè§e¨ o»¹ eª�¹ ¹éíÒºÃiÊu·¸ iì æÃ�¤Çoµ«� ËÃo forsterite/fayalite («è§e» �¹end members ¢o§æÃ�ooÅ iÇÕ¹)

æµ�ã¹ÊÀÒ¾·Õèe» �¹¨Ãi§·Ò§¸Ã³ÕÇi·ÂÒ¹aé¹ æÃ�µ�Ò§æ Áa¡ÁÕäooo¹e¢�ÒÁÒæ·¹·Õè¡ a¹oÂÙ�eÊÁo ¨¹e¡ ié» �¹ solid solution «è§¤u³ÊÁºaµi·Ò§e·oÃ�oÁä´¹ÒÁi¡Ê �¢o§ÊÒÃ·Õèe» �¹ solid solution ¹Õé äÁ�ÁÕ a§¹aé¹µ�o§ãª�¿�§¡ �ªa¹º�§Ê¶Ò¹a (function of state) µ aÇãËÁ � ÁÒª�ÇÂã¹¡ÒÃ»ÃaÂu¡µ�ãª�¡ aºæÃ�äÁ�ºÃiÊu·¸ iì


Chemical Potential«è§¿�§¡ �ªa¹º�§Ê¶Ò¹a a§¡Å �ÒÇ eÃÕÂ¡Ç�Ò Chemical Potential (μ)«è§ e» �¹¾ÒÃÒÁ ieµoÃ�·Õèº�§ºo¡¶§ Ãa aº¾Å a§§Ò¹oiÊÃa¢o§æµ�Åa component ·ÕèoÂÙ�ã¹ÊÒÃµaÇe ÕÂÇ¡ a¹ (phase e ÕÂÇ¡ a¹) ·Õè¾Ã�oÁä·íÒ» i¡ iÃiÂÒ

µaÇoÂ�Ò§eª�¹ æÃ�ooÅiÇÕ¹ ÁÕÊÙµÃe¤ÁÕe»�¹ Fo40Fa60 ËÁÒÂ¤ÇÒÁÇ �Ò æÃ�ooÅiÇÕ¹ íÒ¹Ç¹ 1 phase äÁÕo§¤ �»Ãa¡oº (component) Êo§oa¹¤o Fo æÅa Fa «è§æµ �ÅaµaÇ¡çäÁÕ chemical potential e»�¹¢o§µ aÇeo§

«è§¶ �ÒooÅiÇÕ¹¹ÕéoÂÙ�ã¹ÊÀÒÇaÊÁúÅ ³ ÊÀÒÇaË¹ è§æ (T,P) ¤ �Ò chemical potential ¢o§æµ �ÅaµaÇäe· �Ò¡ a¹ ËÃo μFo = μFa

(นศ. จะไดเรยนเรองนเพมในระดบสงขนไป)

Lecture 11 - Chemical Equilibrium 1

[[Geo]Geo]ChemicalChemical EquilibriumEquilibrium

Chemical WeatheringSedimentation & Diagenesis

Geochemical Reactions: Solubility & PrecipitationCarbonate EquilibriaRedox Dissolution & Eh-pH DiagramAdsorption, Ion Exchange


[Geo]Chemical Equilibrium

¨Ò¡¹iÂÒÁ¢o§¾Å a§§Ò¹oiÊÃa (ΔG): ·u¡æ Ãaººä¾ÂÒÂÒÁ´íÒe¹i¹ä»ã¹·iÈ·Ò§·ÕèäÅ´¾Åa§§Ò¹oiÊÃaãË�µèíÒÊu´ ËÃoe»�¹ÈÙ¹Â � ¹aè¹¤o �Ãaºº� ä¾ÂÒÂÒÁãË �e¢ �ÒÊÙ� �ÊÀÒÇaÊÁ uÅ� (equilibrium) ¹aè¹eo§

« è§ÊÀÒÇaÊÁ uÅ ä¢ é¹oÂÙ�¡aº ou³ËÀÙÁ iæÅa¤ÇÒÁ´ a¹ (e·�Ò¹aé¹!!!) ËÒ¡ T&P e»ÅÕèÂ¹ä» Ãaººä¾ÂÒÂÒÁ»Ã aºãË�e¢ �ÒÊÙ�ÊÁ uÅãËÁ �

µÂ. Ëi¹ pegmatite «è§ÁÕæÃ� feldspar oÒë¤ÂoÂÙ�oÂ �Ò§ÊÁ uÅãµ�¼iÇoÅ¡ æµ�eÁèo¶Ù¡Â¡µaÇ¢é¹ÁÒoÂÙ�º¹¼iÇoÅ¡ « è§ T&P e»ÅÕèÂ¹ä» (æÅaÊÊÒÃÃoºæ µaÇÁ a¹¡çe»ÅÕèÂ¹ä» �ÇÂ eª�¹ ÁÕ¹éíÒ ÁÕ CO2) äe¡ i´¡ÒÃ¼ u¾ a§·íÒÅÒÂ ¡ÅÒÂe» �¹æÃ� i¹


·íÒäÁµ �o§eÃÕÂ¹ Geochemical Equilibrium

e¾ èoo iºÒÂ ¡ÃaºÇ¹¡ÒÃ¼u¾ a§·íÒÅÒÂ ·Õèe¡i´¢ é¹¡aºæÃ �æÅaËi¹

e¾ èoo iºÒÂ ¡ÃaºÇ¹¡ÒÃ sedimentation ËÃ o¡ÒÃµ¡¼Å ¡/¡ÒÃµ¡µa¡o¹¨Ò¡ÊÒÃÅaÅÒÂ ¡ÅÒÂe»�¹æÃ �ËÃ oµa¡o¹ª¹i´ãËÁ �e¾ èoo iºÒÂ ¡ÃaºÇ¹¡ÒÃ diagenesis « è§e»�¹¡ÃaºÇ¹¡ÒÃµ�Ò§æ ·Õèe¡i ¢ é¹¡aºµa¡o¹ µaé§æµ�eÃ ièÁµ¡¨Á ¨¹¡Ãa·aè§¡ÅÒÂe»�¹Ëi¹ « è§e»�¹¡ÒÃe»ÅÕèÂ¹æ»Å§·aé§·Ò§ ¡ÒÂÀÒ¾ ªÕÇÀÒ¾ æÅa·Ò§e¤ÁÕ


Mineral Solubility: Sulfate

CaSO4(s) = Ca2+(aq) + SO4

2-(aq)

¡ÒÃÅaÅÒÂ¢o§æÃ� anhydrite ã¹¹éíÒºÃiÊ u·¸ iì (298K)

[ ] [ ]Δ = − − − −= +=

or product reactantG 553.6 744.5 1321.8

23.7 kJ

23,700 J−⎡ ⎤= = − = ×⎢ ⎥×⎣ ⎦5

sp

23, 700K K exp 7.04 10

8.3143 298.15

Solubility Product


Mineral Solubility: Sulfate


2-(aq)

¡ÒÃÅaÅÒÂ¢o§æÃ� anhydrite ã¹¹éíÒºÃiÊ u·¸ iì (298K) eÁèoÅaÅÒÂæÅ �Ç äµ�o§ÁÕ [Ca2+] = [SO4

2-] o´ÂÊÁÁuµiãË� sulfate ion äÁ�·íÒ» i¡ iÃiÂÒ hydrolysis µ�o¨¹¡ÅÒÂe» �¹ HSO4

- æÅa H2SO4

−

+ − −

−

= ×

= ×

= ×

5sp

2 2 54

2 5

K 7.04 10

[Ca ][SO ] 7.04 10

x 7.04 10+ − − −= = = × = ×2 2 5 3

4[Ca ] [SO ] x 7.04 10 8.4 10 mol/L

¹aè¹¤o ¤ÇÒÁÊÒÁÒÃ¶ã¹¡ÒÃÅaÅÒÂ¢o§ anhydrite ÁÕ¤�Òe·�Ò¡aº 8.4 mmol/L ËÃo (8.4 mmol/L)*(136 g/mol) = 1,141 mg/L


Çi Õ¡ÒÃ¤íÒ¹Ç³·Õè¶Ù¡µ �o§ÁÒ¡¡Ç �Ò

µ�o§ãª�ÊÁ¡ÒÃÊÁ uÅ»Ãa¨ u Charge Balance Equation¼ÅÃÇÁ¢o§»Ãa¨ uºÇ¡ = ¼ÅÃÇÁ¢o§»Ãa¨ uÅº

¶ �ÒÁÕ common-ion effect (¼Å¢o§äooo¹Ã �ÇÁ) ä·íÒãË �¤ÇÒÁÊÒÁÒÃ¶ã¹¡ÒÃÅaÅÒÂe»ÅÕèÂ¹ä» æÅa¶ �Òãª � CBE ¡ÒÃ¤íÒ¹Ç³ä§�ÒÂ¢ é¹


Charge Balance EquationÊÒÃÅaÅÒÂ BaCl2

¨íÒ¹Ç¹»Ãa¨ uÅº =[Cl-] + [OH-] =

¨íÒ¹Ç¹»Ãa¨ uºÇ¡ 2[Ba2+] + [H+]

¹íÒæÃ� anhydrite ÁÒÅaÅÒÂã¹¹éíÒºÃiÊ u·¸ iì

¨íÒ¹Ç¹»Ãa¨ uÅº =2[SO4

2-] + [OH-] =¨íÒ¹Ç¹»Ãa¨ uºÇ¡ 2[Ca2+] + [H+]

¹íÒæÃ� anhydrite ÁÒÅaÅÒÂã¹ÊÒÃÅaÅÒÂ 0.01 M CaCl2¨íÒ¹Ç¹»Ãa¨ uÅº =

2[SO42-] + [OH-] + [Cl-] =

¨íÒ¹Ç¹»Ãa¨ uºÇ¡ 2[Ca2+] + [H+]


Carbonate Equilibria: ÊÁ uÅ¤ÒÃ �ºoe¹µ

CO2(g) + H2O(l) = H2CO3(aq)

ã¹ºÃÃÂÒ¡ÒÈ ÁÕæ¡ �Ê¤ÒÃ �ºo¹äó ço¡ä« � 0.03% (ËÃo 0.0003 atm)

[ ] [ ]Δ = − − − −= +=


8.4 kJ

8,400 J⎡ ⎤= − =⎢ ⎥×⎣ ⎦

8400K exp 0.03376

8.3143 298.15


Carbonate Equilibria: ÊÁ uÅ¤ÒÃ �ºoe¹µ

CO2(g) + H2O(l) = H2CO3(aq)

ã¹ÊÀÒ¾¸ÃÃÁªÒµi (T=298K, P=1atm) æËÅ �§¹éíÒ¸ÃÃÁªÒµiäÁÕ¤ÇÒÁe¢�Á¢�¹¢o§¡Ã´¤ÒÃ�ºo¹i¡ (H2CO3) ¤§·ÕèeÊÁo

−

=

=

≈

2

2 3

CO

2 3

52 3

[H CO ]K

P

[H CO ]0.03376

0.0003[H CO ] 10 mol/L

e¹ èo§¨Ò¡ activity ¢o§¹éíÒ ÁÕ¤ �Òe· �Ò¡ aº 1.0 ¨ §äÁ�»ÃÒ¡¯ã¹ÊÁ¡ÒÃ¤ �Ò¤§·ÕèÊÁ´ uÅ


µ aÇoÂ�Ò§¡ÒÃÅaÅÒÂ¢o§æÃ �¤ÒÃ �ºoe¹µ

กรณทไมเกดปฏกรยา Hydrolysis

กรณทเกดปฏกรยา Hydrolysis

» i¡ iÃiÂÒäÎo´ÃäÅ«iÊ ¤o» i¡ iÃiÂÒ·ÕèÊÒÃe¤ÁÕ·íÒãË�¹éíÒe¡ i´¡ÒÃæµ¡µaÇ


Ion Activity Product (IAP)

ã¹ÊÒÃÅaÅÒÂã´æ ËÒ¡ IAP ¢o§äooo¹ã¹¢o§æ¢ç§ã´æ ÁÕ¤�ÒÊÙ§¡Ç�Ò Ksp æÅ �Ç (ËÃo IAP/Ksp > 1) ¢o§æ¢ç§ a§¡Å �ÒÇ äÁÕ �æ¹Ço¹�Á� Ç�Òäµ¡µa¡o¹ËÃoµ¡¼Å¡

− −= = ×8.35 9spK 10 4.5 10CaCO3(s) = Ca2+

(aq) + CO32-

(aq)

¶ �Òã¹ÊÒÃÅaÅÒÂË¹è§æ ÁÕ [Ca2+] = 4.1x10-4 M, [CO32-] = 7.3x10-4 M

+ − −= ≈ ×2 2 73IAP [Ca ][CO ] 3 10

−

−

×= =

7

8.35sp

IAP 3 1067

K 10a§¹aé¹ æÃ�æ¤Åä«µ� ÁÕæ¹Ço¹�ÁÇ�Òäµ¡µa¡o¹


>

=

<

sp

sp

sp

IAP1

K

IAP1

K

IAP1

K

oÂÙ�ã¹ÀÒÇa Supersaturation � µ¡¼Å¡

oÂÙ�ã¹ÀÒÇaÊÁ uÅËÃ o Equilibrium

oÂÙ�ã¹ÀÒÇa Undersaturation � äÁ�µ¡¼Å¡

¤ÇÒÁËÁÒÂ¢o§ IAP (ion-activity product)

Lecture 12 - Mineral Solubility 1

GeocGeochemical Equilibriumhemical Equilibrium

Activity & Activity CoefficientEffect of Activity on Mineral DissolutionRedox Dissolution (Example)


Activity vs. Concentration

ã¹¡ÒÃ¤íÒ¹Ç³ ÊÁ´ uÅe¤ÁÕ µÒÁËÅa¡æÅ �Ç µ�o§ãª � �activity� äÁ �ãª �¤ÇÒÁe¢ �Á¢ �¹

o´Â activity äÁÕ¤�Ò¹�oÂ¡Ç �Ò¤ÇÒÁe¢ �Á¢ �¹eÊÁoe¹èo§¨Ò¡ã¹ÊÒÃÅaÅÒÂÁÕäooo¹oÂÙ�ÁÒ¡ÁÒÂËÅÒÂª¹i´ « è§äooo¹¢o§æ¤Åe«ÕÂÁä¶Ù¡Å �oÁÃoº �ÇÂäooo¹Åºoè¹æ ·íÒãË� �äÁ �ÊÒÁÒÃ¶·íÒ»¯ i¡iÃ iÂÒä �eµçÁ·Õè� a§¹aé¹ ¤ÇÒÁe¢ �Á¢ �¹(·Õè¾Ã �oÁä·íÒ»¯ i¡iÃ iÂÒ)·Õèæ·�¨Ã i§ ¨§¹�oÂÅ§


2-(aq)

( ) ( )( )

+ −

=2 2

4

4

Ca SO

CaSO

a aK

a

++<2

2Ca

a [Ca ]


Activity vs. Concentration

a§¹aé¹ �activity� äe»�¹µaÇº �§ºo¡¶§ �effective concentration� « è§ËÁÒÂ¶§¤ÇÒÁe¢ �Á¢ �¹·ÕèËÅ§eËÅooÂÙ� « è§¾Ã �oÁä·íÒ»¯ i¡iÃ iÂÒe¤ÁÕµ�oä» ¤ÇÒÁÊaÁ¾ a¹ �ÃaËÇ�Ò§ �activity� æÅa �concentration� ¤o

o´Â γ ¤o activity coefficient « è§ÁÕ¤�Ò¹�oÂ¡Ç �Ò 1 eÊÁo eª �¹ ÊíÒËÃ aºäooo¹æ¤Åe«ÕÂÁ

= γi ia [i]

+ ++= γ2 2

2Ca Ca

a [Ca ]


Activity Coefficient

¤�Ò¢o§ activity coefficient ¤íÒ¹Ç³ä � Ò¡ÊÁ¡ÒÃ

o´Â A e»�¹¤�Ò¤§·Õè« è§¢ é¹oÂÙ�¡aºou³ËÀÙÁ iæÅa¤u³ÊÁº aµiäóieÅç¡µÃ i¡¢o§ÊÒÃÅaÅÒÂ æÅa¤�Ò z ¤ o»Ãa u¢o§äooo¹ æÅa¤�Ò I ¤ o¤�Ò¤ÇÒÁæÃ§äooo¹¢o§ÊÒÃÅaÅÒÂ (Ionic Strength)

⎡ ⎤− γ = −⎢ ⎥+⎣ ⎦

2i

Ilog Az 0.2I

1 I− γ = 2

ilog Az I ËÃoDebye-Huckel

Davies: ãª�ÁÒ¡ã¹·Ò§¸Ã³Õe¤ÁÕ

= ×∑ 2i

1I [i] z

2


Ionic Strength

¨§¤íÒ¹Ç³ËÒ¤ �Ò ionic strength ¢o§ÊÒÃÅaÅÒÂ·Õè»Ãa¡oº �ÇÂ 0.1 M BaCl2 æÅa 0.04 M NaNO3

= ×∑ 2i

1I [i] z

2

{ }

{ }

+ − + −= + + − + + + −

= + + − + + + −

=

2 2 2 2 23

2 2 2 2

1I [Ba ]( 2) [Cl ]( 1) [Na ]( 1) [NO ]( 1)

21

[0.1]( 2) [0.2]( 1) [0.04]( 1) [0.04]( 1)20.34


⎡ ⎤− γ = −⎢ ⎥+⎣ ⎦

2i

Ilog Az 0.2I

1 I

Activity Coefficient

¡íÒË¹´ãË� A = 0.514

a§¹aé¹ activity coefficient ¢o§ Ba2+ ÁÕ¤�Òe·�Ò¡ aº

−

⎡ ⎤− γ = + −⎢ ⎥+⎣ ⎦− γ =

γ = =

2i

i

0.6172i

0.34log (0.514)( 2) 0.2(0.34)

1 0.34log 0.6172

10 0.241


Activity ÁÕ¼ÅoÂ�Ò§äÃ¡ aº ¤ÇÒÁÊÒÁÒÃ¶ã¹¡ÒÃÅaÅÒÂ


2-(aq)

¡ÒÃÅaÅÒÂ¢o§æÃ� anhydrite ã¹ÊÒÃÅaÅÒÂ·ÕèÁÕ I = 0.2 (298K)

[ ] [ ]Δ = − − − −= +=


23.7 kJ

23,700 J−⎡ ⎤= = − = ×⎢ ⎥×⎣ ⎦5

sp

23, 700K K exp 7.04 10

8.3143 298.15

Solubility Product


( ) ( )( )

+ − + −

+ −

+ −

− + −

−

γ γ= =

× = γ γ

× =

2 2 2 24 4

4

2 24

2 2Ca SO 4Ca SO

CaSO

5 2 24Ca SO

5

a a [Ca ] [SO ]K

1a

7.04 10 [Ca ][SO ]

7.04 10 (0.28)(0.28)[x][x]

Activity ÁÕ¼ÅoÂ�Ò§äÃ¡ aº ¤ÇÒÁÊÒÁÒÃ¶ã¹¡ÒÃÅaÅÒÂ

+ −= = =2 24[Ca ] [SO ] x 0.029966 M

¹ aè¹¤o ¤ÇÒÁÊÒÁÒÃ¶ã¹¡ÒÃÅaÅÒÂ¢o§ anhydrite ÁÕ¤ �Òe· �Ò¡ aº 29.966 mmol/L ËÃo (29.966 mmol/L)*(136 g/mol) = 4,075 mg/L

·íÒãË �¤ÇÒÁÊÒÁÒÃ¶ã¹¡ÒÃÅaÅÒÂe¾ ièÁÁÒ¡¢ é¹!!!!


Redox Dissolution

¡ÒÃÅaÅÒÂ¢o§æÃ � (Ê�Ç¹ãË�e»�¹æÃ �« aÅä¿ �) ·ÕèÁÕ¡ÒÃe»ÅÕèÂ¹Ê¶Ò¹aoo¡« ie´ª a¹ �ÇÂ

+ + = +123 2 2 ( l) 2 3 2 3( aq)2FeCO O 2H O Fe O 2H CO

− + ++ + = + +2 2722 2 2 4FeS O H O 2SO Fe 2H

+ − ++ + = +22 2MnO 4H 2e Mn 2H O


µ aÇ¡ÒÃÊíÒ¤ a·Õè·íÒãË�e¡ i´¡ÒÃ¼u¾ a§·íÒÅÒÂ·Ò§e¤ÁÕ

ou³ËÀÙÁi¤ÇÒÁ´ a¹¹éíÒ

¤ÒÃ �ºo¹äóo¡ä«´ � (¡Ã´¤ÒÃ �ºo¹ i¡)oo¡« ie¨¹ (e»�¹µ aÇoo¡« iä´Ê�)¡Ãó è¹æ eª�¹ « aÅ¿�ÇÃ i¡ (ÁÒ¨Ò¡æ¡ �Ê SO2 æÅa SO3)

Lecture 13 - Stability Diagram 1

RedoxRedox, Eh, Eh--pH DiagrampH Diagram

Redox Geochemical ReactionsEh-pH Diagram (Stability Diagram)


¹iÂÒÁ: » i¡ iÃiÂÒoo¡« ie´ª a¹-ÃÕ´ a¡ª a¹

+ + −→ +2 3Fe Fe e

+ − ++ + → +22 2MnO 4H 2e Mn 2H O

Oxidation

Reduction

¤ÒÂoieÅç¡µÃo¹æÅ �ÇeÅ¢oo¡«ie´ªa¹e¾ ièÁ¢é¹

ÃaºoieÅç¡µÃo¹æÅ �ÇeÅ¢oo¡«ie´ªa¹Å´Å§


Èa¡Â�ä¿¿�Ò¢o§» i¡ iÃiÂÒ (E°)

» i¡ iÃiÂÒÃÕ ço¡«� äÁÕÈ a¡Â �ä¿¿ �Ò¢o§µaÇÁ a¹eo§eÊÁo (¶ �ÒäÁ�ÁÕ¤ÇÒÁµ�Ò§È a¡Â � oieÅç¡µÃo¹¡çä¶ �ÒÂoo¹äÁ�ä �) «è§ã¹Ãaºº SI ¡íÒË¹´ãË�¤�Ò E° äµ�o§e» �¹È a¡Â �ä¿¿ �ÒÃÕ a¡ªaè¹eÊÁo

+ − ++ + → +22 2MnO 4H 2e Mn 2H O

+ − ++ →3 2Fe e Fe

Eº = +1.23 V

Eº = +0.77 V

ÃÇÁ¡ a¹ää � + + + ++ + → + +2 2 32 2MnO 4H 2Fe Mn 2H O 2Fe

E = (E°)red – (E°)ox = 1.23-0.77 = 0.46 V


¾Åa§§Ò¹oiÊÃa¡ aºÈa¡Â�ä¿¿�Ò¢o§» i¡ iÃiÂÒ

n = ¨íÒ¹Ç¹oÁÅ¢o§oieÅç¡µÃo¹·ÕèÁÕ¡ÒÃ¶ �ÒÂe·F = ¤�Ò¤§·Õè¿ÒÃÒe´Â � (96487 ¤ÙÅoÁº �/oÁÅ)E = È a¡Â �ä¿¿ �Ò¢o§» i¡ iÃiÂÒ

+ + + ++ + → + +2 2 32 2MnO 4H 2Fe Mn 2H O 2Fe

E = (E°)red – (E°)ox = 1.23-0.77 = 0.46 V

Δ = −o oG nFE Δ = −G nFE

Δ = −= −= −= −

G nFE

(2)(96487)(0.46)

88, 768.04 J

88.8 kJ


Δ = Δ +

− = − +

= −

o

o

o

G G RT ln Q

nFE nFE RT ln Q

RTE E ln Q

nF

Nernst Equation

+ + + ++ + → + +2 2 32 2MnO 4H 2Fe Mn 2H O 2Fe

+ +

+ +

⎛ ⎞= − ⎜ ⎟

⎝ ⎠

3 2 2o

4 2 2

RT [Fe ] [Mn ]E E ln

nF [H ] [Fe ]

+ +

+ +

⎛ ⎞= − ⎜ ⎟

⎝ ⎠

3 2 2

4 2 2

[Fe ] [Mn ]E 0.46 0.0296 log

[H ] [Fe ]

= −o 2.303RTE E logQ

nF


Stability Diagram of Water (Eh-pH)

pH

Eh

(V

)

4 9

0

1.22

Eh = 1.22 – 0.059pH

Eh =–0.059pH

H2O

H2

H2O

O2

æ¼¹ÀÒ¾æÊ´§eÊ¶ÕÂÃÀÒ¾¢o§¹éíÒã¹¸ÃÃÁªÒµ i

Ù¡ÒÃ¤íÒ¹Ç³ �ÇÂÁ o

ÊÀÒ¾oo

¡«iä´Ê�

ÊÀÒ¾

ÃÕiÇ«

�

Eh = E


Eh

(V

)

Stability or Eh-pH Diagram of system Fe(OH)2(s)-Fe(OH)3(s)


Eh-pH Diagram common iron-containing minerals (pyrite, siderite, hematite, magnetite)

eÊ �¹·º ¤o ÁÕ¤ÇÒÁe¢�Á¢�¹¢o§eËÅç¡ [Fe2+] = 10-6 M


æ¼¹ÀÒ¾ Eh-pH eoÒä»ãª �·íÒoaäÃ?µÂ. ¹íÒÁÒ·íÒ¹ÒÂª¹ i´¢o§ �æÃ�� ·Õèäe¡ i´¨Ò¡¡ÃaºÇ¹¡ÒÃ diagenesis ã¹ÊÀÒÇaæÇ´Å �oÁ¢o§¡ÒÃÊaÊÁµa¡o¹æººµ�Ò§æ (or vice versa)

Lecture 14 - Weathering 1

Weathering Weathering ¡ÃaºÇ¹¡ÒÃ¼u¾a§·íÒÅÒÂ¡ÃaºÇ¹¡ÒÃ¼u¾a§·íÒÅÒÂª¹i´¢o§¡ÒÃ¼u¾ a§·íÒÅÒÂ

Physical, Chemical, and Biological»�¨ aÂ·ÕèÁÕ¼Åµ�o¡ÒÃ¼u¾ a§·íÒÅÒÂ

T, P, pH, Eh, Oxygen, CO2, H2O

Êiè§·ÕèeËÅo¨Ò¡¡ÃaºÇ¹¡ÒÃ¼u¾ a§·íÒÅÒÂ·Ò§e¤ÁÕ?What are they and where do they go?


Physical Weathering: ¡ÒÃ¼u¾ a§·Ò§¡ÒÂÀÒ¾

¡ÒÃ¼u¾ a§·íÒÅÒÂ´ �ÇÂ¡Åä¡·Ò§¿ �Êi¡Ê�¢o§¹éíÒ·Õèou³ËÀÙÁiµèíÒ

¡ÒÃæ¢ç§µ aÇæÅa¡ÒÃÅaÅÒÂ-Freeze-thaw weathering¡ÒÃæµ¡Ãaeºi ¨Ò¡¡ÒÃ´Ù ¹éíÒ-Hydration shattering¼Å¡¹éíÒæ¢ç§oµ¢ é¹-Ice-crystal growth æÃ§´ a¹¹éíÒ-Hydraulic pressure


Physical Weathering: ¡ÒÃ¼u¾ a§·Ò§¡ÒÂÀÒ¾

Salt weathering ¡ÒÃe¡ i ¼Å¡e¡Åo ä a¹ãË�Ëi¹æµ¡Wetting and Drying e»�Â¡æ æË �§æ ä¼ue»�¹¡ÒºInsulation weathering ¼ue»�¹æ¶ºæ ËÃoe»�¹ªaé¹æ äæµ¡e»�¹¡Òº Pressure release ¡ÒÃÅ´æÃ§´ a¹ äæµ¡ã¹ÃÙ»¢o§ Joint Stress corrosion cracking æÃ§e¤ �¹æÃ§¡´ a¹¨¹Ëi¹æµ¡


Biological Weathering: ¡ÒÃ¼u¾ a§·Ò§ªÕÇÀÒ¾

¡ÒÃe¨Ãieµiºoµ¢o§¾ ª ÊÒÃ¾ iÉ (¡Ã´µ�Ò§æ) ·Õè¾ ª»Å �oÂoo¡ÁÒ¡ÒÃËÒ¡ i¹¢o§Ê iè§ÁÕªÕÇiµ¢¹ÒéÅç¡ eª�¹æº¤·ÕeÃÕÂ·Õèµ�o§¡ÒÃoo¡« ie¨¹¡ÒÃªo¹äªËÒoÒËÒÃ¢o§ÃÒ¡¾ ªæÃ§ a¹¨Ò¡¡ÒÃ·Õèµ�¹äÁ�ãË�¢é¹¡Ã´·Õèe¡ i´¨Ò¡¡ÒÃe¹�Òe» ��oÂ¼u¾ a§üÅ i¹·ÃÕÂ � (æº¤·ÕeÃÕÂ eËç´ ÃÒ ÏÅÏ)


Chemical Weathering: ¡ÒÃ¼u¾ a§·Ò§e¤ÁÕ

¡ÃaºÇ¹¡ÒÃäÎo´ÃäÅ«ÕÊ (Hydrolysis)

¡ÃaºÇ¹¡ÒÃoo¡« ie´ªaè¹-ÃÕ a¡ªaè¹ (Oxidation -Reduction)¡ÃaºÇ¹¡ÒÃÃ aº¹éíÒæÅaeÊÕÂ¹éíÒ¼Å ¡ (Hydration-Dehydration)¡ÃaºÇ¹¡ÒÃæÅ¡e»ÅÕèÂ¹o ioo¹ (Ion Exchange)

¡ÃaºÇ¹¡ÒÃÅaÅÒÂ (Dissolution)


Hydrolysis

e» �¹» i¡ iÃiÂÒ·Õè¹éíÒæÂ¡µaÇe» �¹äÎo´Ãe¨¹äooo¹ (H+) æÅaäÎ´Ão¡ä«´ �äooo¹(OH-) æÂ¡Â �ÒÂ¡ a¹e¢�Òä»·íÒ » i¡ iÃiÂÒ

Mg2SiO4 + 4H2O → {2Mg2+ +4OH-} + {4H+ + SiO44-}

→ 2Mg(OH)2 + H4SiO4

Silicic Acid


e» �¹» i¡ iÃiÂÒ·Õè¹éíÒe¢�Òä»·íÒ » i¡ iÃiÂÒÃÇÁ¡ aºæÃ�e iÁã¹Å a¡É³a¹éíÒ¼Å¡ ·íÒãË�¼Å¡¢ÂÒÂµaÇoµ¢é¹ æµ�e¹éoo �o¹Å§æÅaÂ a§ÁÕæÃ§ a¹Ãoº·iÈ

2H2O + CaSO4 → CaSO4⋅2H2O¹éíÒ æo¹äÎä´Ãµ�(æ¢ç§) Â i»«aÁ(o �o¹ æÅa ÅaÅÒÂ§�ÒÂ)

¶ �Ò¹éíÒÁÒ¡¡ç¹íÒä»ÊÙ�¡ÒÃÅaÅÒÂ ËÃo dissolution

Hydration


e» �¹¡ÒÃÅ´ËÃoe¾ ièÁoÕeÅç¡µÃo¹ (eÅ¢oo¡«ie´ªa¹) ã¹¸Òµu·Õè»Ãa¡oºe» �¹æÃ�

MnSiO3 + 1/2 O2 +2H2O = MnO2 + H4SiO4

FeS2 + 7/2 O2 +H2O = Fe2+ + 2H+ + 2SO42-

ºÒ§µaÇ¡ç¤§·¹æµ�ºÒ§µaÇ¡çÅaÅÒÂä �§�ÒÂËÃ o¼ueÃçÇ

Oxidation-Reduction


¡ÒÃ¼u¾ a§·íÒÅÒÂ·Ò§e¤ÁÕ¢o§æÃ� »Ãa¡oº �ÇÂ» i¡ iÃiÂÒÁÒ¡¡Ç�ÒË¹è§ª¹iéª�¹ acid-base dissoluion æÅ �ÇµÒÁ �ÇÂ oxidation-reduction

Combination!!


¤ÇÒÁ¤§·¹¢o§æÃ �µ �o¡ÒÃ¼u¾ a§·Ò§e¤ÁÕã¹ÀÒÇa·Õè¼iÇoÅ¡ äÊÇ¹·Ò§¡ aº¡ÒÃµ¡¼Å¡ã¹ Bowen�s Series

¡ÒÃ¼u¾a§·Ò§e¤ÁÕ¢o§æÃ�« iÅie¡µ

¤§·¹

µ�o¡Ò

Ã¼u¾a§e¾ièÁ¢

é¹


¼Å¨Ò¡¡ÒÃ¼u¾ a§·íÒÅÒÂ·Ò§ e¤ÁÕ

o§¤ �»Ãa¡oº·Ò§e¤ÁÕe»ÅÕèÂ¹ä» � oÅÙÁ i¹aÁ (Al) Á a¡ääÁ �e¤Å èo¹Â �ÒÂä»äË¹ æµ�äooo¹o è¹æ Ë¹Õoo¡ä»¨Ò¡o¤Ã§ÊÃ �Ò§ (ÁÒ¡º �Ò§ ¹ �oÂº �Ò§ æÅ �Çæµ�ª¹i´¢o§äooo¹)

o¤Ã§ÊÃ �Ò§¼Å ¡e»ÅÕèÂ¹ä» � æÃ � íÒ¾Ç¡« iÅ ie¡µ Ê�Ç¹ãË�ä¡ÅÒÂe»�¹æÃ � i¹ (clay minerals) « è§ÁÕo¤Ã§ÊÃ �Ò§e»�¹æ¼�¹æ (layers) Ê�Ç¹æÃ � íÒ¾Ç¡¤ÒÃ �ºoe¹µæÅa« aÅä¿ �¹aé¹ ä¡ÅÒÂe»�¹äooo¹ã¹ÊÒÃÅaÅÒÂ


¼Å·Õèe �¹ª a´¢o§¡ÒÃ¼u¾ a§·íÒÅÒÂ ¤ o äeËÅoÊ�Ç¹·ÕèäÁ�¤ �oÂe¤Å èo¹·Õèeª �¹ aluminum æÅaæÃ �eËÅç¡äe¾ ièÁ¢ é¹

eÁèoe¡i´ weathering æÅ�Ç äeËÅooaäÃ?

(I) Ëi¹Ê´(II) Ëi¹¼u(III) Ëi¹¼u(IV)Ë i¹¼u

****

Al2O3 ¤�o¹¢�Ò§¤§·Õè äÁ �e»ÅÕèÂ¹æ»Å§ÁÒ¡¹a¡


eÁèoe¡i´ weathering æÅ�Ç äeËÅooaäÃ?

Ëi¹Ê´ Ëi¹¼u ãË � Al2O3

¤§·Õè¡ÒÃe»ÅÕèÂ¹

æ»Å§

ÁÕ¹éíÒe¾ ièÁ¢é¹ã¹o¤Ã§ÊÃ �Ò§ æÃ�eËÅç¡æÅaoÅÙÁi¹ aÁäÁÕÊ a´Ê �Ç¹e¾ ièÁ¢é¹ e¾ÃÒaäooo¹oè¹æ Ë¹Õä»e¡oºËÁ´

% ¡ÒÃe»ÅÕèÂ¹æ»Å§


Êiè§·ÕèeËÅo¨Ò¡¡ÒÃ¼u¾ a§¢o§æÃ �« iÅie¡µ

Êiè§eËÅ�Ò¹Õé ·íÒãË �e¡ i Êiè§·Õè»Ãa¡oº¡ a¹¢ é¹ÁÒe»�¹ � i¹ (Soil)�

Lecture 15 - Dispersion 1

Dispersion in Secondary Environment Dispersion in Secondary Environment ¡ÃaºÇ¹¡ÒÃ¡Ãa¨ÒÂµ aÇ¢o§¸Òµuã¹ÊÀÒÇaæÇ´Å �oÁ·uµ iÂÀÙÁi¡ÃaºÇ¹¡ÒÃ¡Ãa¨ÒÂµ aÇ¢o§¸Òµuã¹ÊÀÒÇaæÇ´Å �oÁ·uµ iÂÀÙÁi

¡ÒÃ¡Ãa¨ÒÂµaÇ¢o§¸Òµu (Dispersion of Elements) ¤ ooaäÃ?ÊÀÒÇaæÇ´Å �oÁ¡ÒÃ¡Ãa¨ÒÂµaÇ¢o§¸ÒµuÁÕ¡Õè»ÃaeÀ· æÅaÁÕ¤ÇÒÁÊíÒ¤ a

oÂ �Ò§äÃº �Ò§?»�¨ aÂ·Õèe»�¹µaÇ¤Çº¤uÁãË�e¡i´¡ÒÃ¡Ãa¨ÒÂµaÇ¢o§¸Òµu/æÃ �ã¹ÊÀÒÇaæÇ´Å �oÁ

æºº·uµiÂÀÙÁ i


Primary Environ. Dispersion - ¡ÒÃ¡Ãa¨ÒÂµ aÇ¢o§¸Òµuã¹ÊÀÒÇaæÇ´Å�oÁ»°ÁÀÙÁi

ä �æ¡� ã¹Ëi¹oa¤¹Õ

Secondary Environ. Dispersion - ¡ÒÃ¡Ãa¨ÒÂµ aÇ¢o§¸Òµuã¹ÊÀÒÇaæÇ´Å�oÁ·uµ iÂÀÙÁi

ä �æ¡� ã¹æo�§ÊaÊÁµa¡o¹ (sedmentary basin) ËÃ oã¹Ëi¹µa¡o¹

Dispersion ¡ÒÃ¡Ãa¨ÒÂµ aÇ¢o§¸Òµu


¡ÒÃ¡Ãa¨ÒÂµ aÇã¹ÊÀÒÇaæÇ´Å �oÁ»°ÁÀÙÁi - Ëi¹oa¤¹Õ

¸Òµu/æÃ � ·Õèµ¡¼Å¡¨Ò¡¡ÒÃeÂç¹µaÇ¢o§æÁ¡ÁÒ ÁÕoaäÃº �Ò§?o§¤ �»Ãa¡oº¢o§æÁ¡ÁÒäÁÕ¼ÅoÂ �Ò§ÁÒ¡µ�o¡ÒÃe¡ i æÃ � ¶ �ÒæÁ¡ÁÒeÃ ièÁµ�¹ o§¤ �»Ãa¡oºäÁ�eËÁo¹¡ a¹ ää �Ëi¹·ÕèäÁ�eËÁo¹¡ a¹ËÃoÇ i¸Õ¡ÒÃeÂç¹µaÇµ�Ò§¡ a¹ (·aé§æ ·ÕèæÁ¡ÁÒÁÕo§¤ �»Ãa¡oºeËÁo¹¡ a¹) ¡ç·íÒãË �ä �æÃ �µ�Ò§ª¹ i´¡ a¹Important Factors: Thermodynamics & Compositionää �eÃÕÂ¹µ�oä»ã¹¤Ã è§ËÅa§¢o§e·oÁ


eËµuã´¨§µ �o§ÁÕ¡ÒÃ¡Ãa¨ÒÂµ aÇ¢o§¸Òµu/æÃ �

¼ÅÅa¾ �¨Ò¡¡ÒÃ¼u¾a§·íÒÅÒÂ äÁÕºÒ§Ê �Ç¹·Õèe¤Å èo¹·Õèä � (mobile) ä �æ¡ � äooo¹ æÅa¤oÅÅoÂ � «è§äe¤Å èo¹·Õèä»¡ aºµ aÇ¡ÅÒ§ eª �¹ ¹éíÒeÁèoÊ �Ç¹·Õèe¤Å èo¹·Õèä �eËÅ�Ò¹Õé ä»µ¡ÊaÊÁã¹æo�§ÊaÊÁµa¡o¹æË �§ãËÁ�·ÕèÁÕÊÀÒÇaäÁ�eËÁo¹e iÁ (Eh, pH, T, P, etc.) ¡çoÒ¨µ¡µa¡o¹eÃÒeÃÕÂ¡¡ÒÃe¤Å èo¹·Õè¢o§ weathering products ¨Ò¡æËÅ�§e iÁä»ÊÙ�æËÅ�§ãËÁ�Ç �Ò �¡ÒÃ¡Ãa¨ÒÂµ aÇã¹ÊÀÒÇaæÇ´Å �oÁ·uµ iÂÀÙÁi� ËÃo secondary environment dispersion


2o Environment Dispersion: ÁÕæººäË¹º�Ò§?

¡ÒÃ¡Ãa¨ÒÂã¹ÃÙ»¢o§ÊÒÃÅaÅÒÂ¡ÒÃ¡Ãa¨ÒÂã¹ÃÙ»¤oÅÅoÂ �¡ÒÃµ¡¼Å¡¨Ò¡ÊÒÃÅaÅÒÂ¡ÒÃe¡ i æÃ �¨Ò¡¡ÒÃÃ aºËÃoÊÙeÊÕÂ¹éíÒ¡ÒÃe¡ i æÃ �¨Ò¡¡ÒÃe»ÅÕèÂ¹Êiè§æÇ´Å�oÁ (Eh, pH, T, P, water content etc.)


¡ÃaºÇ¹¡ÒÃ Dispersion


¡ÒÃæÂ¡Â �ÒÂ¢o§ weathering products ã¹ÃÙ»¢o§äooo¹ã¹ÊÒÃÅaÅÒÂ

¡Åu�Á·Õè 1: ÊÒÁÒÃ¶¤§oÂÙ�ã¹ÊÒÃÅaÅÒÂä´ �o´ÂäÁ�µ¡µa¡o¹ ¶§æÁ�Ç �ÒÊÒÃÅaÅÒÂäÁÕ pH ÊÙ§

¡Åu�Á·Õè 2: äµ¡µa¡o¹e»�¹ÊÒÃ»Ãa¡oºäÎ´Ão¡ä«´ � · aé§æ ·ÕèÊÒÃÅaÅÒÂoÒ¨ÁÕ pH äÁ�ÊÙ§¹ a¡

¡Åu�Á·Õè 3: ÁÕ»ÃaüÊÙ§ «è§äÃÇÁµ aÇ¡ aºoo¡«ie¨¹e»�¹ÊÒÃ»Ãa¡oºeªi§«�o¹ eª�¹ SO4

2-


Electrical double layer ¢o§o¹uÀÒ¤¤oÅÅoÂ �·íÒãË�e¡i´¡ÒÃ¼Åa¡¡ a¹äÁ�µ¡¨Á§�ÒÂæ

æµ�ã¹ÊÒÃÅaÅÒÂ·ÕèÁÕ¤ÇÒÁæÃ§äooo¹ÊÙ§æ (high ionic strength) eª�¹ ºÃieÇ³»Ò¡æÁ �¹éíÒ (¹éíÒ¡Ã�oÂ) ¤ÇÒÁË¹Ò¢o§ªaé¹ EDL äÅ´Å§ ·íÒãË�o¹uÀÒ¤¤oÅÅoÂ �e¤Å èo¹·ÕèÁÒµi´¡ a¹æÅ �Çµ¡µa¡o¹ e» �¹ i¹ó¹ÊÒÁeËÅÕèÂÁ


æÃ �·Õè¾ºã¹ 2o Environment

¡ÒÃµ¡¼Å ¡¨Ò¡¤oÅÅoÂ �ä´ �æ¡ � cryptocrystalline quartz (flint, chert, jasper)

¡ÒÃµ¡¼Å ¡¨Ò¡ÊÒÃÅaÅÒÂeª�¹ gypsum, halite, sylvite (ÃÇÁeÃÕÂ¡Ç �Ò evaporites)

¡ÒÃe¡ i´æÃ�¨Ò¡¡ÒÃÃaºËÃoÊÙeÊÕÂ¹éíÒeª�¹ gypsum ↔ anhydrite

¡ÒÃe¡ i´æÃ�¨Ò¡¡ÒÃe»ÅÕèÂ¹Ê iè§æÇ´Å �oÁ (Eh, pH, T, P, water content etc.) ÊÀÒÇaæÇ´Å �oÁe»ÅÕèÂ¹ä» ·íÒãË� mobility ¢o§æÃ�e»ÅÕèÂ¹ä» �ÇÂ


ÊÃu»: ¡ÃaºÇ¹¡ÒÃ¡Ãa¨ÒÂµ aÇ¢o§ weathering products

Lecture 16 - Diagenesis 1

DiagenesisDiagenesis:: ¡ÒÃe»ÅÕèÂ¹æ»Å§·Õèe¡i´¢ é¹¡aºµa¡o¹¡ÒÃe»ÅÕèÂ¹æ»Å§·Õèe¡i´¢ é¹¡aºµa¡o¹ã¹æo �§ÊaÊÁµa¡o¹¨¹¡Ãa· aè§¡ÅÒÂe»�¹Ëi¹ã¹æo �§ÊaÊÁµa¡o¹¨¹¡Ãa· aè§¡ÅÒÂe»�¹Ëi¹

¤ÇÒÁËÁÒÂ¢o§ diagenesiseËµu»�¨ aÂ·Õè·íÒãË�e¡i´ diagenesis ã¹æo �§ÊaÊÁµa¡o¹¡ÃaºÇ¹¡ÒÃ diagenesis ·Õèe¡i ¡aºµa¡o¹

o¹i¹·ÃÕÂ � (inorganic sediments)oi¹·ÃÕÂ � (organic sediments)

æÅa¼ÅÅa¾ �·Õèä �¨Ò¡¡ÃaºÇ¹¡ÒÃ diagenesis

This lecture was partially taken & modified from 205237’s lecture (Dr. Benjavun Ratanasthien).


»ÃaÇ aµ i¡ÒÃe¡ i´¢o§Ëi¹µa¡o¹ ÊÒÁÒÃ¶·Õèäæº�§oo¡e» �¹ 3 Ãa´ aº´ a§¹Õé

1. Sedimentogenesis- ¡ÒÃe¡i µa¡o¹2. Diagenesis - ¡ÒÃe»ÅÕèÂ¹æ»Å§¢o§µa¡o¹

¨¹¡Ãa· aè§¡ÅÒÂe»�¹Ëi¹µa¡o¹3. Catagenesis - e»�¹ÃaÂaeÇÅÒ¡ÒÃe»ÅÕèÂ¹æ»Å§¢o§e»Åo¡oÅ¡·ÕèäÁÕ¼Åµ �oËi¹µa¡o¹ « è§e»�¹eÇÅÒ·ÕèÂÒÇ¹Ò¹ÁÒ¡


¡ÒÃe»ÅÕèÂ¹æ»Å§ã¹æo �§ÊaÊÁµa¡o¹Diagenesis of Sediments in Sedimentary Basins

Diagenesis ¤ o¡ÒÃe»ÅÕèÂ¹æ»Å§·Ò§e¤ÁÕæÅa¿�Êi¡Ê�¢o§µa¡o¹ ¹aºµaé§æµ�ÇÒÃa·Õèä �µ¡Å§ÁÒÊÙ�æo �§ÊaÊÁµa¡o¹ ¨¹¶§ÃaÂa·Õèe»�¹ pre-erosion oÕ¡ÇÒÃaË¹è§ o´ÂoÂÙ�ÀÒÂäµ�oi·¸i¾Å¢o§

¡ÃaºÇ¹¡ÒÃ·Ò§e¤ÁÕæÅa¿�Ê i¡Ê � (Chemical & Physical Processes)ÊÀÒ¾·Ò§e·¤o·¹i¡ æÅaÀÙÁ i»Ãae·È ·aé§ã¹¡ÒÃÊaÊÁµaÇæÅa¡ÒÃe¡ÅÕèÂ¼iÇ i¹ (Tectonic and morphological conditions in both fields ofaccumulation and denudation)

æÃ�·ÕèÁa¡ä¾ºã¹¸ÃÃÁªÒµi e» �¹¼Å¢o§·aé§¡ÒÃµ¡µa¡o¹ æÅa¡ÒÃe»ÅÕèÂ¹æ»Å§ËÅ a§¨Ò¡¡ÒÃÊaÊÁµa¡o¹


Diagenesis Ê�Ç¹ãË�äe¡ i´ºÃieÇ³ã¡Å �æ ¼iÇoÅ¡


SyndiagenesisInitial stage (Acid-Base, Redox, Hydrolysis,

Precipitation, etc.)Early burial stage (dolomitization, hydration,

ion-exchange)Anadiagenesis

Deep Burial StageLithification(Metamorphism)

EpidiagenesisPre-erosion

¡ÃaºÇ¹¡ÒÃe»ÅÕèÂ¹æ»Å§ËÅa§¨Ò¡ÊaÊÁµa¡o¹


¡ÃaºÇ¹¡ÒÃe»ÅÕèÂ¹æ»Å§ËÅa§¨Ò¡ÊaÊÁµa¡o¹


µ aÇoÂ �Ò§: ¡ÒÃe»ÅÕèÂ¹æ»Å§·Õèe¡ i´¡ aºµa¡o¹

ÁÕ¡ÒÃÅaÅÒÂe¾ ièÁ¢ é¹ (dissolution)ÁÕ¡ÒÃµ¡µa¡o¹ÁÒ¾o¡o¹uÀÒ¤æÃ �e iÁ (precipitation) eª �¹ cementation ¨Ò¡æ¤Åä«µ �ËÃ o¤Çoµ« � Ò¡ÊÒÃÅaÅÒÂ¹éíÒãµ� i¹e¡i »¯ i¡iÃ iÂÒ oxidation-reduction ¡aºµa¡o¹µa¡o¹æ¤Åä«µ �ÁÕ¡ÒÃæÅ¡e»ÅÕèÂ¹äooo¹ (Ion-Exchange) ¨¹ºÒ§Ê�Ç¹¡ÅÒÂe»�¹oóÅäÁµ� (dolomite, CaMg(CO3)2)

ÁÕ¡ÒÃÃº¡Ç¹¨Ò¡Ê iè§ÁÕªÕÇ iµeÅç¡æ (·aé§¾ªæÅaÊaµÇ �) � burrowËÃ ooÒ¨¶Ù¡¤ÇÒÁÃ �o¹-¤ÇÒÁ¡´ a¹ ·íÒãË�o¤Ã§ÊÃ �Ò§¢o§µa¡o¹e»ÅÕèÂ¹


Diagenesis ¹ aé¹ ¹o¡¨Ò¡ä¢é¹oÂÙ�¡ aº T, P æÅ �Ç Å a¡É³a¢o§ÊÀÒÇaæÇ´Å �oÁ (Eh, pH) ¡çÂ a§ÁÕ¼Åµ�oª¹i´¢o§¡ÃaºÇ¹¡ÒÃµ�Ò§æ ·Õèe¡ i´¡ aºµa¡o¹ã¹æo �§ÊaÊÁµa¡o¹ �ÇÂ

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จิรัฏฐ แสนทนit.geol.science.cmu.ac.th/~ssaenton/205237/All_Lectures.pdf · Lecture 1 - Introduction 5 Textbooks {Krauskopf, K.B., and D.K. Bird. 1995. Introduction