Prepare for your exams
Get points
Guidelines and tips
Sell on Docsity
Docsity AI

Prepare for your exams

Study with the several resources on Docsity

Earn points to download

Earn points by helping other students or get them with a premium plan

Guidelines and tips

Sell on Docsity

Docsity AI

Prepare for your exams

Study with the several resources on Docsity

Find documents

Prepare for your exams with the study notes shared by other students like you on Docsity

Search for your university

Find the specific documents for your university's exams

Docsity AINEW

Summarize your documents, ask them questions, convert them into quizzes and concept maps

Explore questions

Clear up your doubts by reading the answers to questions asked by your fellow students

Earn points to download

Earn points by helping other students or get them with a premium plan

Share documents

20 Points

For each uploaded document

Answer questions

5 Points

For each given answer (max 1 per day)

All the ways to get free points

Get points immediately

Choose a premium plan with all the points you need

Study Opportunities

Choose your next study program

Get in touch with the best universities in the world. Search through thousands of universities and official partners

Community

Ask the community

Ask the community for help and clear up your study doubts

Free resources

Our save-the-student-ebooks!

Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors

Learning Objectives - Geochemistry - Lecture Slides, Slides of Geochemistry

Acharya Nagarjuna University Geochemistry

In these Lecture Slides, the Lecturer has put emphasis on following key points : Learning Objectives, Thermodynamics, Geochemistry, Mass Flux, Thermodynamic Models, Phase Diagrams, Visualize, Minerals, Aqueous, Interpretations

Typology: Slides

2012/2013

Uploaded on 07/25/2013

rajdulari 🇮🇳

(6)

68 documents

1 / 18

This page cannot be seen from the preview

Don't miss anything!

Learning Objectives and Fundamental Questions

• What is thermodynamics and how are its concepts

used in geochemistry?

• How can heat and mass flux be predicted or

interpreted using thermodynamic models?

• How do we use phase diagrams to visualize

thermodynamic stability of minerals and aqueous

solutions?

• How do kinetic effects affect our interpretations

from thermodynamic models? - We will address

this later in the class.

Docsity.com

Discover Slides of Geochemistry Acharya Nagarjuna University

Partial preview of the text

Download Learning Objectives - Geochemistry - Lecture Slides and more Slides Geochemistry in PDF only on Docsity!

Learning Objectives and Fundamental Questions

What is thermodynamics and how are its concepts

used in geochemistry?

How can heat and mass flux be predicted or

interpreted using thermodynamic models?

How do we use phase diagrams to visualize

thermodynamic stability of minerals and aqueous

solutions?

How do kinetic effects affect our interpretations

from thermodynamic models? - We will address

this later in the class.

What is Thermodynamics?

• Thermodynamics: A set of of mathematical

models and concepts that allow us to describe the

way changes in the system state (temperature,

pressure, and composition) affect equilibrium.

Can be used to predict how geological systems ( e.g.

melts-minerals; solutes in aqueous solutions) will

respond to changes in state

Invert observed chemical compositions of minerals and

melts to infer the pressure and temperature conditions

or origin

Thermodynamic Systems - Definitions

Isolated System: No matter

or energy cross system

boundaries. No work can be

done on the system.

Open System: Free exchange

across system boundaries.

Closed System: Energy can be

exchanged but matter cannot.

Adiabatic System: Special case

where no heat can be exchanged

but work can be done on the

system (e.g. PV work).

Thermodynamic State Properties

• Extensive: These variables or properties

depend on the amount of material present

(e.g. mass or volume).

• Intensive: These variables or properties DO

NOT depend on the amount of material

(e.g. density, pressure, and temperature).

Spontaneous Reaction Direction

Energy and Work

Energy: commonly defined as the capacity to do work ( i.e.

by system on its surroundings); comes in many forms

Work: defined as the product of a force (F) times times a

displacement acting over a distance (d) in the direction

parallel to the force

work = Force x distance

Example: Pressure-Volume work in volcanic systems.

Pressure = Force/Area; Volume=Area x distance;

PV =( F/A)(Ad) = Fd = w

Heat Capacity Defined

An increment of heat, Δq, transferred into a body produces a

proportional incremental rise in temperature, ΔT, given by

Δq = Cp * ΔT

where Cp is called the molar heat capacity of J/mol-degree

at constant pressure; similar to specific heat, which is based

on mass (J/g-degree).

1 calorie = 4.184 J and is equivalent to the energy necessary

to raise 1 gram of of water 1 degree centigrade. Specific heat

of water is 1 cal /g °C, where rocks are ~0.3 cal / g °C.

First Law of Thermodynamics

The increase in internal energy as a result of

heat absorbed is diminished by the amount of

work done on the surroundings:

dE

i

= dq - dw = dq - P d V

By convention, heat added to the system, dq,

is positive and work done by the system, dw,

on its surroundings is negative.

This is also called the Law of Conservation of Energy

Reaction Deltas

Thermodynamics uses well established formalism. One

of the most widespread shorthands is the reaction delta.

the example below is for molar volume change, but it

can be extended to other molar properties and state variables.

Reaction Notation: ΔV = V

final

V initial

aA + bB + … = mM + nN + …

V = mM + nN + … - aA - bB - …

V = V

Al2O3*3H2O

V Al2O - 3V H2O

Note that the r subscript

is added to show that

the Δ

V corresponds

to a chemical reaction.

The ° superscript is

added to show that the

thermodynamic data are for

standard state conditions.

V

= V

Al 2 O 3 " 3 H 2 O °

# V

Al 2 O 3 °

# 3 V

H 2 O °

We will do an example on the board.

Additivity of State Variables

State variables may be added or subtracted in order to

calculate the value for a particular reaction, mineral, etc.

C + O 2 = CO 2 !r H ° = "393.509 kJmol

1 CO + 1 2 O 2 = CO 2 !r H ° = "282.984 kJmol
1 Subtracting the reactions - this means reverse the 2nd reaction and change the sign of !r H ° , we get C + 1 2 O 2 = CO !r H ° = "110.525 kJmol
1 This allows us to calculate the enthalpy of formation for CO from C and O 2 , a reaction that is impossible to complete in the lab. The method is extensible to other state variables and molar properties. This of course is appropriate because the thermodynamic state variable’s value, for example the enthalpy of formation ONLY depends on the “state” of the system and not the “path” to reach some specific state.

Enthalpy of Melting

580°C

Learning Objectives - Geochemistry - Lecture Slides, Slides of Geochemistry

Related documents

Partial preview of the text

Download Learning Objectives - Geochemistry - Lecture Slides and more Slides Geochemistry in PDF only on Docsity!

Learning Objectives and Fundamental Questions

used in geochemistry?

interpreted using thermodynamic models?

thermodynamic stability of minerals and aqueous

solutions?

from thermodynamic models? - We will address

this later in the class.

What is Thermodynamics?

• Thermodynamics: A set of of mathematical

models and concepts that allow us to describe the

way changes in the system state (temperature,

pressure, and composition) affect equilibrium.

melts-minerals; solutes in aqueous solutions) will

respond to changes in state

melts to infer the pressure and temperature conditions

or origin

Thermodynamic Systems - Definitions

Isolated System: No matter

or energy cross system

boundaries. No work can be

done on the system.

Open System: Free exchange

across system boundaries.

Closed System: Energy can be

exchanged but matter cannot.

Adiabatic System: Special case

where no heat can be exchanged

but work can be done on the

system (e.g. PV work).

Thermodynamic State Properties

• Extensive: These variables or properties

depend on the amount of material present

(e.g. mass or volume).

• Intensive: These variables or properties DO

NOT depend on the amount of material

(e.g. density, pressure, and temperature).

Spontaneous Reaction Direction

Energy and Work

by system on its surroundings); comes in many forms

displacement acting over a distance (d) in the direction

parallel to the force

work = Force x distance

Example: Pressure-Volume work in volcanic systems.

Pressure = Force/Area; Volume=Area x distance;

PV =( F/A)(Ad) = Fd = w

Heat Capacity Defined

An increment of heat, Δq, transferred into a body produces a

proportional incremental rise in temperature, ΔT, given by

Δq = Cp * ΔT

where Cp is called the molar heat capacity of J/mol-degree

at constant pressure; similar to specific heat, which is based

on mass (J/g-degree).

1 calorie = 4.184 J and is equivalent to the energy necessary

to raise 1 gram of of water 1 degree centigrade. Specific heat

of water is 1 cal /g °C, where rocks are ~0.3 cal / g °C.

First Law of Thermodynamics

The increase in internal energy as a result of

heat absorbed is diminished by the amount of

work done on the surroundings:

dE

i

= dq - dw = dq - P d V

By convention, heat added to the system, dq,

is positive and work done by the system, dw,

on its surroundings is negative.

This is also called the Law of Conservation of Energy

Reaction Deltas

Thermodynamics uses well established formalism. One

of the most widespread shorthands is the reaction delta.

the example below is for molar volume change, but it

can be extended to other molar properties and state variables.

Reaction Notation: ΔV = V

aA + bB + … = mM + nN + …

V = mM + nN + … - aA - bB - …

V = V

Note that the r subscript