CHEM 481 Lecture Notes _Engle 2nd - Chapter 1_

CHEM 481 Lecture Notes _Engle 2nd - Chapter 1_ - Chapter 1...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Last printed 1/10/2010 2:46 PM 1-1 Chapter 1- Equations of State G ETTING S TARTED Consider the following. You have a beaker filled with two chemical substances, A & B. The goal of thermodynamics is to develop a theoretical framework that can predict whether or not A & B spontaneously mix, and if they don’t under what conditions (P, T) will they. A & B spontaneously react, and if they don’t under which conditions do they. What is the equilibrium composition? Need to develop (i) theoretical framework and (ii) mathematical description of chemical systems. Our path will generally be as follows: 9 Develop a framework for describing systems (vocabulary) 9 One-Component Systems - Gases (Ideal Gases, Real Gases) 9 Energy Transactions (Heat & Work) 9 Spontaneous Change (Entropy, Free Energy) 9 Equilibrium A A A A A B B B B A A B D A B B C B Energy Transactions (q, w, U, H) Spontaneous Change (S, G, A, μ) Chemical Equilibrium Mixtures Chemical System (Solids, Liquids, Gases, Inert mixtures, Reactive Mixtures Real Systems : Difficult (if not impossible to describe mathematically, e.g. V=V(P,T) is difficult to write down for “silly putty” Model Systems : Contain approximate form of intermolecular interactions. Mathematically tractable, but limited. (e.g. ideal gas) Application Theoretical Framework (Generally Applicable)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Last printed 1/10/2010 2:46 PM 1-2 We will then examine in more detail the following 9 Real Gases 9 One-Component Systems - Phase transitions (Solids, Liquids, Gases) 9 Two-Component Systems – Mixtures (Liquids, Gases) T HERMODYNAMIC S YSTEMS For the purpose of thermodynamics, the universe is divided into two parts. System : The part of the universe that we are interested in. Surroundings : Everything else The system and surroundings are separated by a boundary that either allows or prohibits the exchange of matter and energy. Types of Systems: Open Boundary allows exchange of matter and energy Closed Boundary allows exchange of energy Isolated Boundary allows exchange of neither Systems can be composed of one (or more) phases. .. Heterogenous system Two-phase system (Water/ice) or (Oil/Water) Homogenous system Single phase throughout Water Matter Energy Matter Energy Matter Energy System : The part we are interested in Surroundings “The Universe” Boundary
Background image of page 2
Last printed 1/10/2010 2:46 PM 1-3 In order to answer the questions posed above, we need a quantitative way of describing the state of a system. T HE S TATE OF A S YSTEM Microscopic State – The microscopic state is defined by specifying the position (r) G and momentum(p) G for every atom in the system. Follow motion of each atom by solving Newton’s equations. But, in order to define the microscopic state, we must specify 6 numbers for each atom ! Most detailed description Æ System is viewed as a collection of a large number of atoms or molecules that are under constant motion Appeals to Chemist’s chemical intuition because system properties (e.g. T Boil , T Melt , expansion coefficient, compressibility. ..) stem from the forces that atoms and molecule exert on each other. (H
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 13

CHEM 481 Lecture Notes _Engle 2nd - Chapter 1_ - Chapter 1...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online