120 likes | 336 Views
Welcome to CHEM 471. Course webpage http://setanta.unl.edu/CHEM471 or Blackboard. Syllabus http://setanta.unl.edu/CHEM471/syllabus.pdf or Blackboard. Instructor: Gerard S. Harbison, 723 Hamilton Hall. Telephone 472-9346. gerry@gerry.unl.edu.
E N D
Welcome to CHEM 471 Course webpage http://setanta.unl.edu/CHEM471 or Blackboard Syllabus http://setanta.unl.edu/CHEM471/syllabus.pdf or Blackboard Instructor: Gerard S. Harbison, 723 Hamilton Hall. Telephone 472-9346. gerry@gerry.unl.edu Office hours: Monday 2:00 p.m. - 4:00 p.m. or by appointment. Teaching Assistant: Yali Wang, Hamilton Hall 724, telephone 472-9474. CHEM 471: Physical Chemistry Ms. Wang’s office hours: Wednesdays 2:00-4:00 pm and Fridays 12:00-2:00pm in the Resource Room Lectures: MWF, 10:30 a.m. - 11:20 p.m. in Hamilton Hall 133. Power Point presentations will be available at http://setanta.unl.edu/CHEM471/notes/or on Blackboard.
Transcript health warning! I STRONGLY COUNSEL AGAINST TAKING THIS COURSE WITHOUT HAVING COMPLETED MATH 107, OR EQUIVALENT, AND CHEM 221. IGNORE THIS ADVICE AT YOUR OWN RISK! CHEM 471: Physical Chemistry
Welcome to CHEM 471 • Recitations: Tuesday, 10:30 a.m. - 11:20 a.m., Hamilton Hall 133 • Thursday, 10:00 p.m. - 10:50 p.m., Henzlik Hall 109 • Unannounced quizzes will occasionally be given in recitation for extra credit. Homework: 30% of the total grade. Handed out on Friday of odd-numbered weeks; due a week later. 25% penalty for unexcused, less-than-a-week-late homework. Homework not accepted more than a week late. Each question or part of a question will be graded on three-tier system: • 100% if you solved the problem completely and correctly • 50% if you failed to solve the problem completely and correctly, but in the opinion of the grader understood and used the correct approach to solving the problem. • 0% points if you blew it completely. CHEM 471: Physical Chemistry Text: Physical Chemistry: Principles and Applications in the Biological Sciences, by Tinoco, Sauer, Wang, Puglisi, Harbison, and Rovnyak. First ten chapters. Extra credit will be awarded, at my discretion, for intelligent positive criticism of the text. Don’t tell me, email me!
Welcome to CHEM 471 Grading: Homework (x 7): 30%, midterms (x 3) 45%, final 25% . Midterms held in room to be announced, from 6:30 - 8:00 p.m. in the evening. Final at regularly scheduled time (Friday May 9, 7:30 a.m. - 9:30 a.m.) Grading: Letter grades will be assigned as follows. CHEM 471: Physical Chemistry In general, we don’t offer more than 50% partial credit on any problem, usually much less. In the real world, it’s important to get it right, not mostly right!
Welcome to CHEM 471 Expectations: This may be the toughest course you’ll ever take at UNL. I make no apologies for that. Outside of reci, you need to set aside at least 5 hours a week for it. I expect you to pay active attention. This means not just listening, but thinking about what has been said. I expect you to read the assigned text in advance. I expect you to be able to answer questions on it in class. I award extra credit for particularly good questions in lecture,and intelligent answers when I call on you. CHEM 471: Physical Chemistry Attendance and active participation in recitation is also expected I award extra credit for catching non-trivial mistakes in the notes, lectures or text
Welcome to CHEM 471: schedule CHEM 471: Physical Chemistry Grading: Letter grades will be assigned as follows. This page is on the World Wide Web at http://setanta.unl.edu/CHEM471/syllabus.html.
Introduction: basic units The Système International (SI) is a system of units based on the meter, kilogram and second. http://physics.nist.gov/cuu/Units/index.html SI units are the only units we will use in this course. The second is the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. The meter is the length of the path traveled by light in vacuum during a time interval of 1/299792458 of a second. The kilogram is the unit of mass; it is equal to the mass of the international prototype of the kilogram. CHEM 471: Physical Chemistry http://www.foxnews.com/science/2013/01/07/kilogram-has-gained-weight/
Introduction: more basic units The ampere is the constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 x 10–7 Newton per meter of length. The Kelvin, the unit of thermodynamic temperature, is the fraction 100/27316 of the thermodynamic temperature of the triple point of water (0.01 C) The mole is the amount of substance of a system that contains a number of particles equal to the number of atoms in exactly 0.012 kg of isotopically pure carbon 12. That number is Avogadro’s constant and is approximately (6.02214179 ± 0.00000030) x 1023 mol–1 CHEM 471: Physical Chemistry http://physics.nist.gov/cuu/Constants/index.html
Introduction: derived units Acceleration has units of meters per second squared (m s–2) For example, the acceleration due to gravity at the earth’s surface is 9.8 m s–2 Force is derived from acceleration via Newton’s second law: f= ma. The SI unit of force is the Newton; 1 N = 1 kg m s–2 So the force exerted by an object of 1 kg in the earth’s gravitational field is 9.8 N; weight is a kind of force. A Newton isn’t much force; it’s the weight of a 102 g object (3 1/2 ounces). Pressure is force per unit area. Since the SI unit of area is m2, the SI unit of pressure, the Pascal; 1 Pa = 1 N m–2 = 1 kg m–1 s–2 CHEM 471: Physical Chemistry Because a meter squared is quite a large area, a Pascal is a very small unit of pressure. Because it’s so small, we often use two other units. 1 bar = 105 Pa 1 atm = 101325 Pa The SI units of volume are m3 This is a volume much larger than chemists or biochemists are used to dealing with, and so we tend to work in L or mL. 1000 L = 106 mL = 1 m3
Introduction: unit conversions Example: The usual chemists’ units of density and molecular weight are g/mL and g/mol respectively. Convert these to SI units. Answer: 1 g/mL × 106 mL/m3 × 10–3 kg/g = 103 kg/m–3 1 g/mol × 10–3 kg/g = 10–3 kg/mol = 10–3 kDa Example: The minimum central pressure recorded for Hurricane Dean was 906 mbar. Convert that to Pascals and Megapascals CHEM 471: Physical Chemistry Answer: 906 mbar × 10–3 bar/mbar × 105 Pa/bar = 90,600 Pa = 0.0906 MPa http://en.wikipedia.org/wiki/Hurricane_Dean
Introduction: the force of a H3 Exercise 1.1: a Hummer H3 has a typical mass of 4700 lb. What downward force does it exert on the earth? Answer: first we convert out of medieval units. 2.205 lb = 1 kg, so we can multiply by (1/2.205) kg/lb and it’s the same as a multiplication by 1. 4700 lb x (1/2.205) kg/lb = 2132 kg. CHEM 471: Physical Chemistry Now, taking the acceleration due to gravity as 9.80665 m s–2, we apply Newton II: f = ma = mg = 2132 kg x 9.80665 m s–2 = 20903 N
Introduction: for Wednesday… Read pages 13 - 19! CHEM 471: Physical Chemistry