1275 Words6 Pages

Chemistry 457 - Statistical Thermodynamics, Final Exam
Wednesday, June 11, 2008; 8:30 am - 10:20 am
Name (please print clearly) [1 point].: This is a closed book exam. Only simple calculators are allowed. No graphing or programmable calculators will be permitted. Two cheat sheet are allowed. Please write neatly and be sure to show all work for each problem in the space provided. Useful constants: kB = 1.38 × 10−23 JK−1 , h = 6.626 × 10−34 Js, NA = 6.022 × 1023 mol−1 Problem 1 - Short answers [14 points]. No more than one word or equation is required per response. a) What is the Boltzmann factor? b) What are the units of the heat capacity? c) What are the units of the molecular partition function? d) How many vibrational modes does ethanol have? e) What is the high temperature molar vibrational heat capacity of HCN? f ) How does the molecular mean free path depend on pressure in the hard-sphere model? g) How does the diﬀusion constant D for a molecule or atom scale with temperature? h) What is the SI unit of viscosity? i) How does the viscosity of a gas depend on pressure in the hard-sphere model? j) How does the average molecular speed scale with temperature? k) What is the maximum occupation number ni for Fermions? l) How does the heat capacity scale with temperature in the Debye model for low temperatures? m) How many optical phonon branches does a crystal with 4 atoms per unit cell have? n) What are the names of the two (Austrian and the American) scientists who laid the foundations of statistical thermodynamics
1
Problem 2 - Basic thermodynamics [30 points]. Provide a short explanation possibly with equation or illustrating graph if necessary: a) State and explain the equipartition theorem and its relation to a system’s degrees of freedom.
b) Sketch the experimental setup for the Brownian motion experiment shown in class and discuss the result and

Related

## Student Essay

1448 Words | 6 PagesB. How does the change in temperature affect the volume of the container? Get the Gizmo ready: Activity A: Boyle’s law Set the temperature (T) to 300 K. Check that the mass (m) is set to 0 kg. Question: How does pressure affect the volume of a gas? 1.

## Chemistry Experiment (Peka)

531 Words | 3 PagesBerry List of Chemistry Experiments (PEKA) Form 4 (Part 1) Chapter 2 – The Structure of the Atom List of PEKA experiments: 1. Diffusion of particles in a gas, liquid and solid 2. Rate of diffusion depends on the temperature 3. Rate of diffusion depends on the mass of the gas particles 4. Melting and freezing points of naphthalene, C10H8 Number | Activity 2.1 | Pg.

## Alkanes Essay

371 Words | 2 PagesAlkanes - CnH2n+2 Trends in melting point, boiling point and volatility can be explained by the weak intermolecular forces called induced dipole - induced dipole forces (van der Waal's forces). As the chain length of alkanes increases, so does the number of electrons, which increases the strength of the van der Waal forces. Branching reduces the surface area over which induced dipole - induced dipole forces can act. Alkanes are non-polar molecules, so do not react with polar reagents. Free radicals are produced by the homolytic fission of covalent bonds, for which light can provide energy.

## Energetics Experiment Essay

2151 Words | 9 PagesEnergetics Aim: To measure the energy released from the complete combustion of a known mass of alcohol or paraffin wax, to heat water. Hypothesis: The combustion of alcohols is exothermic. In this experiment the energy is released from burning a known mass of alcohol in order to heat a known amount of water. A comparison of various alcohols and paraffin wax (methanol, ethanol, propanol, butanol, octanol and candle) as fuels can be made by calculating the quantity of energy transferred to the water. In this experiment, the amount of energy (heat) involved in a chemical change will be determined.

## Boyle's Law

337 Words | 2 PagesGas Laws A gas law is described as a mathematical generalization of the relationships among the amount, pressure, temperature, and volume of a gas (p 168). Boyle’s law p. 168 Of the several relationships that exist among gas law variables, the first to be discovered relates gas pressure to gas volume. It was formulated over 300 years ago, in 1662, by the British chemist an physicist Robert Boyle. Boyle’s law states that the volume of a fixed mount of a gas is inversely proportional to the pressure applied to the gas if the temperature is kept constant. This means that if the pressure on the gas increases, the volume decreases proportionally; conversely, if the pressure decreses, the volume increases.

## Physics Experiment 6 Results and Discussion

985 Words | 4 Pages4. Results and Discussion Specific heat capacity refers to the amount of heat needed to raise or lower the temperature of a substance. This amount of heat is directly proportional to the mass of the material. In the first activity, the specific heat of a metal, in our case aluminum, was calculated (Table 1). The following formula was used: cm=mwcwT3-T1+mcccT3-T1 mmT2-T3 Where cw is the specific heat capacity of water and cc is the specific heat capacity of calorimeter.

## Essential Calculus Essay

1073 Words | 5 PagesUniversity of Alabama in Huntsville Math 201 Section 1, Spring 2008 Final Exam: MATH 201 Section 1 Full Name: ................................................................................................ Student ID Number............................................................. Note: You need to SHOW all your WORK in order to have full CREDIT. The use of CALCULATOR is prohibited during the exam. There are 10 problems (30 points each ) on the Exam and one bonus problem worths 40 points on this Final Exam. Read each question carefully The Final is 2 and 1/2 hours long or 150 minutes Homework and Quizzes: 150 pts Midterms: 550 pts Final Exam : 300 pts Final Grade over 1000 Letter Grade Note that you need at least 600/1000 to make a grade of C − .

## Molecular Weight By Dumas Method

325 Words | 2 PagesMolecular Weight by Dumas Method In your text (Chang, 10th Ed) : 5.4 The Ideal Gas Equation, especially the Density and Molar Mass of a Gaseous Substance subsections Purpose: The experimental determination of the molecular weight of a volatile liquid sample and the density of its vapor are used to illustrate the uses of the Ideal Gas Law. Background: The Ideal Gas Law is: PV = nRT (Eqn. 1) where P = pressure in atm, V = volume in L, T = temperature in K, and R = 0.082056 L atm/(mol K), the Gas Constant It describes, with good precision, the behavior of many real gases over a wide range of pressures and temperatures. Even when there is deviation from ideality, it is useful as a starting point in physical analysis Recalling that density is mass/volume, Eqn. 1 can be re-written to derive the equation for the density of a gas, assuming ideal behavior: n = P Now multiply both sides by MW: n(MW) = P (MW) V RT V RT n(MW) is # moles x grams/mol = grams = mass, m Therefore: m = (P)(MW) = d , density (mass/volume, in grams/ liter ) (Eqn.

## Calorimetry Essay

773 Words | 4 Pages1 q= Cs x g x T Q represents heat. Specific heat (Cs) is multiplied to the mass (g) and temperature change that occurred in the reaction. ( T). Specific heat is defined as the amount of energy required to raise the temperature of 1 g of a substance by 1 K, under a constant pressure. Considering the fact that substances have differences, the specific heat varies depending on what substance is being heated.

## If You Rest, You Rust

5642 Words | 23 PagesPU11 Physics Question Bank – Heat & Thermodynamics One mark questions 1. In a Carnot engine, the temperature of the sink is 27 C and that of the source is 327 C . What is the efficiency of the Carnot engine? Ans: 1 2. T2 273 27 300 1 1 1 T1 273 327 600 2 How is the efficiency of a Carnot engine affected by the nature of the working substance?

### Student Essay

1448 Words | 6 Pages### Chemistry Experiment (Peka)

531 Words | 3 Pages### Alkanes Essay

371 Words | 2 Pages### Energetics Experiment Essay

2151 Words | 9 Pages### Boyle's Law

337 Words | 2 Pages### Physics Experiment 6 Results and Discussion

985 Words | 4 Pages### Essential Calculus Essay

1073 Words | 5 Pages### Molecular Weight By Dumas Method

325 Words | 2 Pages### Calorimetry Essay

773 Words | 4 Pages### If You Rest, You Rust

5642 Words | 23 Pages