Study-Unit Description

Study-Unit Description


TITLE Chemical Thermodynamics and Kinetics

LEVEL 02 - Years 2, 3 in Modular Undergraduate Course



DESCRIPTION 1. Internal energy: open, closed and isolated systems; heat and work - the sign conventions; internal energy and internal energy changes, U and ΔU; state functions; the first law of thermodynamics.

2. Enthalpy: definition of enthalpy and enthalpy changes, H and ΔH; thermochemical equations, standard conditions and conventions of standard conditions; relationship between U and ΔH; Hess's law; ΔH for various processes; heats of formation; combustion; bond dissociation; phase change; solution; calculation of ΔH(reaction) from enthalpy changes of formation, bond energies, Hess cycles; variation of ΔH with temperature; heat capacities: constant volume heat capacity, Cv, and constant pressure heat capacity, Cp; Kirchoff's equation; applications; measurement of ΔH.

3. Entropy: The second law of thermodynamics, Clausius inequality; quantitative measures of ΔS: entropy changes during the phase change, Trouton's rule, changes in entropy during isothermal expansions of an ideal gas, changes in entropy during the heating of an ideal gas; variation of ΔS with temperature; combining the first and second laws of thermodynamics - the fundamental equations of thermodynamics the third law of thermodynamics - absolute entropies; entropy and chemical processes;ΔS in chemical reactions; the use of ΔS of the universe to predict chemical reactivity.

4. Free energy functions: prediction of chemical reactivity by concentrating on the system - the free energy functions; Helmholtz free energy; Gibbs free energy; properties of the Gibbs free energy, pressure dependence of the Gibbs free energy, temperature dependence of the Gibbs free energy (The Gibbs-Helmholtz equation.)

5. Chemical potential, simple mixtures, chemical reactions and equilibria: definition of chemical potential, chemical potential for a pure substances, pure ideal gases, pure liquids, pure real gases; chemical potential for mixtures of ideal gases - partial molar Gibbs free energy, the fundamental equation of chemical thermodynamics; mixtures, Gibbs-Duhem equation; gaseous mixtures, the chemical potential of gaseous solutions, Gibbs energy, entropy and enthalpy of mixing, liquid mixtures, chemical potential of ideal liquid solutions, ideal-dilute liquid solutions, real liquid solutions - activities, Gibbs energy, entropy and enthalpy of mixing for liquids, colligative properties, chemical reactions and equilibria, reaction Gibbs energy and equilibria, response of equilibria to external disturbances: Le Chatelier's principle, response of equilibria to pressure, response of equilibria to temperature (van't Hoff equation), applications to selected systems: metal ore reduction (Ellingham diagrams), acids/bases.

6. Chemical Kinetics - Introduction, experimental techniques, temperature dependence of reaction rates (Arrhenius equation).

7. Empirical Reaction Kinetics: identification of the rate law and the calculation of rate constant k from experiments; the determination of the rate law from: the isolation method; method of initial rates; the integration method; fractional lifetime method, comparison of these methods. Reactions approaching equilibrium, Relaxation techniques.

8. Elementary reaction kinetics: definition of elementary reactions, molecularity of a reaction, molecularity vs. order, rate laws of elementary reactions , consecutive elementary reactions, variations of concentrations with time, the rate-determining step, the steady state approximation, pre-equilibria.

9. Chemical kinetics for various processes: enzyme reactions - The Michaelis-Menten mechanism (an example of consecutive elementary reactions); Lindemann-Hinshelwood Mechanism - First-order gas phase kinetics - Unimolecular Reactions, relationship between the overall rate constant of a composite reaction (Exemplified through the Lindemann-Hinshelwood mechanism), Chain Reactions: the rate laws of chain reactions, example of a chain reaction having a simple rate law - The Rice-Herzfeld mechanism for the pyrolysis of ethanal in the absence of air, example of a chain reaction having a complicated rate law - The formation of HBr from hydrogen and bromine, special case: explosions, catalysis and oscillation: catalysis, autocatalysis, oscillating reactions.

10. A theoretical approach to chemical kinetics: collision theory, reaction profile in the collision theory, derivation of the rate law through the collision theory, activated complex theory, the reaction profile in the ACT, derivation of the rate law through the ACT (the thermodynamic derivation), the activated complex theory and reactions between ions.

11. Experimental techniques related to chemical thermodynamics, kinetics and other aspects of physical chemistry.

Study-Unit Aims:

This study-unit aims to introduce the students to the principles of classical chemical thermodynamics and kinetics and how these principles can be used to predict the feasibility and rate of chemical processes. Furthermore, students will also be trained to perform physical chemistry experiments related to chemical thermodynamics and kinetics as well as interpret the results of these experiments.

Learning Outcomes:

1. Knowledge & Understanding:

By the end of the study-unit the student will be able to:
- Recall definitions and laws related to heat transfer and work done, on or by a system under specific conditions;
- Explain the concepts related to heat transfer and work done during chemical processes;
- Define enthalpy and entropy and explain how these are affected by changes in conditions;
- Recall and explain the three laws of thermodynamics;
- Explain how entropy or Gibbs energy can be used to predict whether a process is feasible under a set of conditions;
- Apply the concepts of chemical equilibrium and the response of chemical equilibria to temperature and pressure.

2. Skills:

By the end of the study-unit the student will be able to:
- Carry out calculations which can predict reactivity under a set of conditions;
- Work out rate laws for various reaction mechanisms;
- Perform experiments in physical chemistry and collect data from them in safe and reliable manner;
- Check the correctness and reliability of experimental results from physical chemistry experiments;
- Interpret correctly and verify the results of experimental work related to physical chemistry;
- Discuss results of experimental work in relation to established knowledge physical chemistry and chemistry in general;
- Report the findings of an experiment in a scientific manner.

Main Text/s and any supplementary readings:

Main Text:

Atkins' Physical Chemistry, Peter W. Atkins and Julio de Paula, 10th ed., 2014.

Supplementary Reading:

Students Solutions Manual for Atkins' Physical Chemistry, Charles Trapp, Carmen Giunta and Marshall Cady 10th ed., 2014.

ADDITIONAL NOTES Please note that a pass in the Practical component is obligatory for an overall pass mark to be awarded.

STUDY-UNIT TYPE Lecture, Independent Study, Practicum & Tutorial

Assessment Component/s Assessment Due Resit Availability Weighting
Practical [See Add. Notes] SEM1 No 20%
Examination (2 Hours) SEM1 Yes 80%

LECTURER/S Joseph Noel Grima

The University makes every effort to ensure that the published Courses Plans, Programmes of Study and Study-Unit information are complete and up-to-date at the time of publication. The University reserves the right to make changes in case errors are detected after publication.
The availability of optional units may be subject to timetabling constraints.
Units not attracting a sufficient number of registrations may be withdrawn without notice.
It should be noted that all the information in the description above applies to study-units available during the academic year 2020/1. It may be subject to change in subsequent years.