Lab Packet for Chem 457 Experimental Physical Chemistry

160 Pages·2017·28.021 MB·English

by  Bratoljub H. Milosavljevic

Lab Packet
FOR
CHEM 457
Experimental
Physical
Chemistry
Spring, 2017
Instructor: Dr. Bratoljub H. Milosavljevic
Revised: January, 2017

Foreword
Experimental Physical Chemistry, CHEM 457 course is designed to reinforce the
theoretical Physical Chemistry courses with the introduction of physical chemistry
applications in a laboratory environment. Placing abstract concepts in an experimental
framework, physical chemistry may become more self-explanatory and more enjoyable.
This laboratory course mainly utilizes fast kinetics, thermodynamics, electrochemistry,
surface chemistry, and spectroscopy experiments. The topics for this course are chosen
to improve the science and engineering students theoretical and experimental physical
chemistry backgrounds and skills. In addition, each student will work on a special
project to demonstrate her/his independent ability in performing literature searches,
planning and designing the experiment, interpreting the data, communicating in written
scientific language, by writing a paper in the format of a Physical Chemistry Journal, and
in verbal scientific language, by presenting a poster. The synopsis of the eleven
experiments performed in this course is given below.
1) Dissociation of a Propionic Acid Vapor
The equilibrium constant for the dissociation of propionic acid dimer in the vapor
phase will be determined as a function of temperature. From this data, thermodynamic
constants and enthalpy and entropy changes will be calculated. The change in enthalpy is
a measure of the strength of the hydrogen bonds in the dimer.
2) Adsorption from Solution
An adsorption isotherm will be constructed for the adsorption of acetic acid onto
charcoal. Using this isotherm, the surface area of the charcoal will be determined. The
relation between adsorption and surface chemistry will be introduced.
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3) The determination of thermodynamic functions of the reactions in commercial
alkaline-manganese dioxide galvanic cell (Duracell®)
Temperature resolved measurement of the electromotive force of AA Duracell®
galvanic cell will be performed in order to determine the thermodynamic parameters such
as ~rG0, ~rS0 and ~rH0•
4) Real Gas Behavior: Determination of the Second Virial Coefficient of C02
The pressure vs. amount of COi relation under isochoric condition will be studied
in order to determine departure from ideal behavior in the pressure range 0 to 10 bar. The
data obtained will also be used to determine the second virial coefficient of C02.
5) Nanosecond Laser Photolysis Study of Pyrene Fluorescence Quenching by r
Anion
Pyrene in its singlet excited state oxidizes iodide anion. The pyrene fluorescence
decays in the presence of various iodide concentrations will be measured using pulse
laser photolysis technique in order to determine the second order reaction constant.
6) Modeling Stretching Modes of Common Organic Molecules with the Quantum
Mechanical Harmonic Oscillator
The use of the harmonic oscillator model to interpret a vibrational spectroscopy
will be introduced. Using a refined value for the effective single-bond force constant,
stretching mode frequencies will be estimated to within about ±10% with a simple
calculation.
7) Resonance Energy of Naphthalene by Oxygen Bomb Calorimetry
The resonance energy of naphthalene will be determined by calculating its
standard enthalpy of combustion both experimentally using bomb calorimeter and by
using bond energies.
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8) Pyrene Excimer Formation Kinetics
Combined steady state fluorimetry and time resolved laser photolysis
measurements will be performed in order to explore a complex kinetic system comprising
two parallel and two consecutive reactions, that is, to determine the kinetic rate constants
associated with pyrene excimer formation and decay using laser photolysis.
9) Polypropylene Phase Transitions Studied by Differential Scanning Calorimetry
The enthalpy of melting and T g of two different polypropylene samples will be
measured using a first class research grade instrument as an illustration of a typical
industrial problem solved in material chemistry labs.
10) Fluorometric Determination of the Rate Constant and Reaction Mechanism for
Ru(bpy)32+ Phosphorescence Quenching by 02
A Stem-Volmer plot will be constructed to find an experimental kq for the
quenching of Ru(bpy)32+ by oxygen The fundamental principles of fluorescence
measurements as well as quenching mechanisms will be covered.
11) Determining the Spin-Lattice Relaxation (Tt) of 1-Hexanol using 13C-NMR
The spin-lattice times (T1) of each C atom of n-hexanol will be determined by using
NMR spectroscopy. The inversion recovery method will be utilized to obtain T1 times of
C atoms of n-hexanol. The observed times will be related to atomic motion of C
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Table of Contents
I. Preliminaries
1. Forward ................................................................................ .
2. Table of Contents..................................................................... 1v
3. General Information.................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v111
II. The Experiments
1. Dissociation of a Propionic Acid Vapor
Objectives.............................................................................. 1-1
Introduction... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Laboratory Procedure................................................................ 1-5
In Lab Questions..................................................................... 1-12
Data Analysis......................................................................... 1-13
Report Questions..................................................................... 1-15
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
2. Adsorption from Solution
Objectives.............................................................................. 2-1
Introduction............................................................................ 2-1
Laboratory Procedure................................................................. 2-4
In Lab Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
Data Analysis.......................................................................... 2-6
Report Questions...................................................................... 2-9
References.............................................................................. 2-9
v
3. The determination of thermodynamic functions of the reactions in
commercial alkaline-manganese dioxide galvanic cell (Duracell®)
Objectives.............................................................................. 3-1
Introduction............................................................................ 3-1
Laboratory Procedure................................................................. 3-2
Data Analysis......................................................................... 3-4
References............................................................................. 3-5
4. Real Gas Behavior: Determination of the Second Virial Coefficient of
C02
Objectives.............................................................................. 4-1
Introduction ............................................... :............................ 4-1
Laboratory Procedure................................................................. 4-4
Data Analysis.......................................................................... 4-6
Report Questions...................................................................... 4-7
References.............................................................................. 4-7
5. Nanosecond Laser Photolysis Study of Pyrene Fluorescence Quenching
by 1- Anion
Objectives.............................................................................. 5-1
Introduction............................................................................ 5-1
Laboratory Procedure................................................................. 5-5
Data Analysis.......................................................................... 5-7
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6. Modeling Stretching Modes of Common Organic Molecules with the
Quantum Mechanical Harmonic Oscillator (QMHO)
Objectives........................................................................... 6-1
Introduction............................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6-1
Laboratory Procedure............................................................... 6-10
In Lab Questions.................................................................... 6-13
Data Analysis.................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 6-14
Report Questions.................................................................... 6-15
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16
7. Resonance Energy of Naphthalene by Bomb Calorimetry
Objectives.............................................................................. 7-1
Introduction........................................................................... 7-1
Laboratory Procedure................................................................ 7-11
In Lab Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 -1 7
Data Analysis......................................................................... 7-18
Report Questions..................................................................... 7-22
References ............................................................................ 7-22
8. Pyrene Excimer Formation Kinetics
Objectives.............................................................................. 8-1
Introduction............. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Laboratory Procedure................................................................. 8-3
Data Analysis.......................................................................... 8-5
References.............................................................................. 8-8
vu
9. Polypropylene Phase Transitions Studied by Differential Scanning
Calorimetry
Objectives.............................................................................. 9-1
Introduction........................................................................... 9-2
Laboratory Procedure................................................................ 9-3
Data Analysis......................................................................... 9-5
References............................................................................. 9-5
10. Fluorimetric Determination of the Rate Constant and Reaction
Mechanism for Ru(bpy)32+ Phosphorescence Quenching by 02
Objectives.............................................................................. 10-1
Introduction............................................................................ 10-1
Laboratory Procedure................................................................. 10-8
In Lab Questions...................................................................... 10-9
Data Analysis.......................................................................... 10-10
Report Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-10
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 10-10
11. Determining the Spin-Lattice Relaxation (Ti) of 1-Hexanol using
13C-NMR
Objectives.............................................................................. 11-1
Introduction............................................................................ 11-1
Laboratory Procedure................................................................. 11-8
In Lab Questions... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-18
Data Analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11-19
Report Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-19
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . 9-19
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3. General Information
Instructor: Dr. Bratoljub H. Milosavljevic
331C Whitmore, 865-7481, bhml [email protected]
Office Hours: As announced in class and by appointment
Prerequisite: CHEM450
Materials Needed
1) CHEM 457 Lab Packet.
2) Lab notebook with alternate tear-out carbonless copy pages.
3) A flash drive.
4) Approved safety gogg]es.
Eye Protection
There are three types of eye protection acceptable for use in the Penn State
Undergraduate Chemistry Labs. You MUST wear one of these models in the laboratory
AT ALL TIMES!
1) Safety Glasses: Comfortable and offer better peripheral vision compared to gogg]es.
However, they offer less protection than goggles. The bookstore has Panaspec Plus
(Bouton).
2) Visor goggles: Reasonably comfortable, good splash protection, better peripheral
vision than goggles. The Penn State Bookstore carries, Visorgogs (Jones and
Company).
3) Goggles: The highest level of splash protection. However, fog may build up and
limit peripheral vision. There are four different kinds of goggles available at the Penn
State Bookstore.
Course Requirements
You need to complete eight experiments, and a special project to fulfill the
requirements of this laboratory course. A student should submit the following for each