Review Topics for Exam Two                                   Physical Chemistry II 331W            

Spring 2005                             Lycoming College                                       Dr. Mahler


Please note that almost all of the ‘discussion questions’ are useful (i.e. the first several exercises for each chapter);


Chapter 24, Sections 24.1, 2, 3, 4, 5, and 6.


Kinetic Theory of ideal gases; Molecular motion in gases; Various speeds (mean, rms, etc.); Mean free path, collision flux and collision frequency; Effusion and Graham’s Law; Flux and the three transport properties of ideal gases – diffusion, thermal conductivity, viscosity (and their coefficients and units); Molecular motion and viscosity in liquids; Conductance and (molar) conductivity, limiting molar conductivity, strong and weak electrolytes; Kohlrausch’s Law, law of independent migration of ions, degree of ionization, α, or deprotonation, and Ostwald’s Law.

Chapter 24: Exercises 5, 8, 9 (mean speed, mean free path, collision frequency), 11 (collision flux), 12 (effusion), 14 (thermal conductivity), 16, 17 (effusion), 28 (limiting molar conductivity).



Chapter 25, all sections (all, 1-8, 8b new)


Kinetics - some lab techniques for measuring it (real time, flow, and stopped flow methods, flash photolysis, quenching, isolation and initial rates methods); rate, stoichiometric number and rate of formation/consumption; rate laws, rate constant (and units), order (overall and of individual species, indefinite order); differential and integrated rate laws (0th, 1st, 2nd order); half-lives and k; Reactions approaching equilibrium - relaxation and temperature jump method; Arrhenius equation and parameters (activation energy and frequency factor), temperature dependence of rate;. Reaction Mechanisms; Elementary reactions – molecularity; observed vs. predicted (theoretical) rate laws; Consecutive elementary reactions; Three assumptions used to determine rate laws from mechanisms: rate determining step, steady state approximation, pre-equilibrium (plus uses, conditions of each); Kinetic isotope effect (primary and secondary) and causes; Unimolecular reactions and the Lindemann-Hinshelwood mechanism, assumptions needed to make it first and second order;* Activation energy of a composite reaction – positive and negative activation energies.


Chapter 25: Exercises 6, 7, 8 (rates, rate laws, rate constants), 9, 10 (orders of reaction), 11 (1st order), 12 (2nd order), 14 (skip – too involved), 15 (3rd order), 16 (Arrhenius parameters), Problems 1 (experiment to rate law), 12, 18 (mechanisms).


The practice problems are also useful here.


Chapter 26, Sections 1, 2, 3, 4, 5, 6, 7, 11, 12.

Use of the three assumptions to determine rate laws from mechanisms (rate determining step, steady state approximation, pre-equilibrium); Chain reactions; chain carriers; steps in a chain mechanism initiation, propagation, retardation, inhibition, termination); rate laws for chain mechanisms; explosions (thermal and chain-branching); explosion limits in H2 + O2 à H2O; Polymerization kinetics; Stepwise and Chain polymerization and mechanisms; kinetic chain length; Homogenous catalysis and Enzyme kinetics, Michaelis-Menten mechanism, maximum velocity and turnover number; Inhibition (three types); Autocatalysis (brief); Photochemical processes and mechanisms; Quantum yield (primary and overall); Photochemical rate laws; Photosensitization; brief quenching.


Chapter 26: Exercises 5, 6, 8, 9 (all solving mechanisms), 10 (Michaelis Menten), 11, 12 (photochemistry), Prob. 6, 12 (more mechanisms).


Chapter 27, Section 1

Molecular reaction dynamics;  Collision theory and using collision frequency to get collision density; Limitations on collision theory - steric requirements and activation energy; steric factor p and harpoon theory.


Chapter 27: Exercises 4, 5, 7 (all collision theory), (15, 17 – not yet covered);