Chemistry 451 CHEM 451 PHYSICAL CHEMISTRY ( 3 credits) Introduction to chemical principles, including properties of matter and fundamentals of chemical thermodynamics. Prerequisites: CHEM 013, MATH 141, PHYS 202 or PHYS 212 Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-1
Chemistry 451 Physical Chemistry: Quantitative and theoretical study of the properties and structure of matter and their relation to the interaction of matter and energy. This course serves as am introduction to chemical thermodynamics, giving you an understanding of basic principles, laws, and theories of physical chemistry that are necessary for chemistry, biochemistry, pre-medical, general science, and engineering students. Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-2
Chemistry 451 By performing well in this course you should: gain abilities in quantitative problem solving develop the ability to use original thought (and logic) in the solution of problems and the derivation of equations. What about the mathematics? Equations should not obfuscate the science! Mathematics should paint a clear picture of the physical phenomena being studied. Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-3
Administrative Details Meets M, W, and F from 1:25 PM until 2:15 PM During class, you must silence or turn off all cell phones, pagers, etc. Any disruption of class will result in being asked to leave. Office Hours: Monday, Tuesday, Thursday, Friday: 11:00 AM - 12:00 PM Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-4
Office Location 331 Whitmore Lab Whitmore Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-5
Class Web Page http://courses.chem.psu.edu/chem451/index.html On-line now: Still to come: syllabus, book web link syllabus updates (if any) lecture notes (abridged) schedule of classes (reading) homework assignments exam schedules and answers additional fun links Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-6
Grading 2 mid-term exams 20% each 40% Lecture problems (~12) and quizzes (5-7) 25% prob 10% quiz 35% Final exam 25% 25% Total 100% Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-7
Exams and Assignments (1) Two Midterms: all at 6:30 7:45 PM Wed., 18 February 2004 Mon., 5 April 2004 Final Exam: as scheduled by university Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-8
Exams and Assignments (2) You MUST let me know by Wednesday 21 January 2004 of any conflicts with these exams. After that time, only universitysanctioned events (exams, etc.) will be considered as valid excuses. Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-9
Exams and Assignments (3) Lecture Problems: assigned on Monday, due on Wednesday before 1:30 PM. You must work independently on these short problems. Homework: assigned but not collected Quizzes: 5-9 ten-minute quizzes will occur on Wednesdays (no advance warning) Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-10
Physical Chemistry Thermodynamics - relationship between energy interconversion by materials and the molecular properties Kinetics - rates of chemical processes Quantum Mechanics - phenomena at the atomic and molecular scale Statistical Mechanics - relationship between individual molecules and the bulk properties of matter. Spectroscopy - non-destructive interaction of light (energy) and matter, used to study chemical structure. Photochemistry - interaction of light and matter with the intent of altering molecular structure. Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-11
Course Outline http://www.whfreeman.com/pchem7/ We will approach this first course in Physical Chemistry following along the lines of Chap. 1-10 (Part 1: Equilibrium) in Atkins and de Paula, Physical Chemistry, with one or two small excusions Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-12
Course Outline 1 - The properties of gases 24.1 - The kinetic theory of gases 2 - The First Law: the concepts 3 - The First Law: the machinery 4 - The Second Law: the concepts 5 - The Second Law: the machinery 6 - Physical transformations of pure substances 7 - Simple mixtures 8 - Phase diagrams 9 - Chemical equilibrium 10 - Equilibrium electrochemistry Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-13
The Structure of Physical Chemistry http://www.whfreeman.com/pchem7/content/chapter0.htm All in-class links should appear on class web page Matter and Energy Quantification Partitioning Equivalence Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-14
Matter Composed of electrons and nuclei (neutrons and protons) which can be further divided (but not here) into subatomic particles. Matter has the following physical properties: Mass - largely due to nuclei Electronic moments - monopole (charge) is most important Magnetic moments - dipole is most important Spin - least tangible of properties (some useful classical analogies) Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-15
Quantification of Matter Substance: a pure form of matter Amount of substance (n): reported in terms of moles. 1 mol of a substance contains as many entities as exactly 12 g of carbon-12 (around 6.02 x 10 23 entities). Avogadro s constant: N A = 6.0221 x 10 23 mol -1 Extensive property: dependent upon the amount of matter in the substance (e.g. mass, volume) Intensive property: independent upon the amount of matter in the substance (e.g. pressure, temperature) Molar property: X m, an extensive property divided by the amount of substance. X m = X/n (now an intensive property) Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-16
Units - SI (see http://physics.nist.gov/cuu/units/) Systeme Internationale (mks) has seven base units: Base quantity Name Symbol Length meter m Mass kilogram kg Time second s Electric current ampere A Thermodynamic temperature kelvin K Amount of substance mole mol Luminous intensity candela cd Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-17
SI Derived Units Derived quantity Name Symbol Volume cubic meter m 3 Speed (velocity) meter per second m/s or m s -1 Acceleration meter per second squared m/s 2 or m s -2 Wave number reciprocal meter m -1 Mass density kg per cubic meter kg/m 3 or kg m -3 Frequency hertz Hz: s -1 Force newton N: kg m s -2 Pressure, stress pascal Pa: N/m 2 : kg m -1 s -2 Energy,work, heat joule J: N m: kg m 2 s -2 Power watt W: J/s: kg m 2 s -3 Electric charge coulomb C: A s Electric potential volt V: W/A: kg m 2 s -3 A -1 Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-18
Energy Energy: the capacity to do work Work: motion against an opposing force Conservation of energy: the total energy of an isolated system is unchanged by any process. Energy is neither created nor destroyed - it can be transferred from one location to another in the form of mechanical work or heat. Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-19
Work Sign convention to be explained dw = F z dz w = z 2 F z = dw dz F z dz = F z z 2 z 1 z 1 ( ) F z z 1 z 2 Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-20
Contributions to Energy Kinetic Energy, E k : Energy an object possesses as a result of its motion Potential Energy, V: Energy an object possesses as a result of its position Gravitational potential energy Electrical potential energy E k = 1 2 mv 2 V G = mgh q1q 2 V E = 4πε 0 r Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-21
Energy: Units SI unit of energy - the joule (1 J = N m = 1 kg m 2 s -2 ) Molar energy - J mol -1 or (more useful) kj mol -1 Other useful units of energy: Electronvolt: Calorie: 1 ev = 1.6602176 x 10-19 J 1 cal = 4.184 J (exactly) Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-22
Energy: Partitioning Molecules have a certain number of degrees of freedom: they can rotate, vibrate, and translate - many properties depend upon these degrees of freedom. Equipartition theorem: All degrees of freedom have the same average energy at temperature T; total energy is partitioned over all possible degrees of freedom. Quadratic energy terms: 1 mv 2 2 x + 1 mv 2 2 y + 1 mv 2 2 z Average energy associated with each quadratic term is 1/2 kt where k = 1.38 x 10-23 J K -1 (the Boltzmann constant). However, this is a classical result so care must be taken in its application to atomic and molecular systems. Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-23
Energy: Quantization At the atomic level, not all physical properties are explained by Newtonian (classical) mechanics. Einstein, Schrödinger, Heisenberg, Planck, and others developed and demonstrated that at atomic and molecular levels a quantum mechanics was needed where energy of particles is not a continuum, but rather is quantized. At the molecular level rotations, vibrations, and the motions of electrons (electronic transitions) must have quantized energy levels. Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-24
How are Energy and Matter Related? 1. Dual nature of light Wave nature of light interference - two light waves produced near to one another will interfere constructively and destructively Particle nature of light light has been shown (Einstein) to behave in particlelike packets called photons Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-25
How are Energy and Matter Related? 1. Dual nature of light Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-26
How are Energy and Matter Related? 2. Dual nature of matter? Particle nature of matter central to our understanding of the classical world Wave nature of matter the De Broglie relation: λ = h/p Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-27
How are Energy and Matter Related? 2. Dual nature of matter - electrons diffract! Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-28
Mathematics Preparation Concepts you must already know Basic algebra, trigonometry, and geometry Differentiation in one variable Integration Concepts we will help you with Partial differentiation More difficult integration (line integrals, etc.) Prof. Mueller/Sykes Chemistry 451 Spring 2004 Lecture 1-29