Study Guide for Exam 2 s2

Chemistry 480A

Study Guide for Exam 2

1. You should know from memory: The temperature and pressure dependence of G and G G = H  TS for a constant temperature process The Gibbs-Helmholtz equation The formula for entropy of mixing for ideal solutions The expressions for chemical potential for ideal gases, nonideal gases, and solutions The differential form of the combined first and second laws for an open system The integrated form of the combined first and second laws for an open system

The definition of the chemical potential, i The definitions of activity and activity coefficient o The relationship between Kthermodynamic and rG

The equation for rG when reaction components are not in their standard states The Gibbs phase rule The Clapeyron and Clausius-Clapeyron equations The definition of an ideal solution Raoult's law and Henry's law The definition of partial molar volume and other partial molar quantities The expression for osmotic pressure The expression for ionic strength o The relationship between rG for the cell reaction and the emf of the cell The formula for ionic strength The Nernst equation Eo for the standard hydrogen electrode o o o E = ER - EL The electrochemical cell conventions

2. You should know how to: Calculate the fugacity of a nonideal gas given the equation of state Write expressions for H, A, and G from the integrated form for U o o Calculate rG at 25 C and other temperatures. o o Calculate Kthermodynamic from G and vice versa at 25 C o Calculate Kthermodynamic at temperatures other than 25 C Sketch and/or analyze a one-component phase diagram (p as a function of T) Use the Clapeyron and Clausius-Clapeyron equations to calculate various properties of materials Calculate the vapor pressure of a substance under an applied external pressure Calculate the partial molar volume given appropriate volume and composition data

Derive expressions for Smix, Hmix and etc. for ideal solutions Find vapor pressures of, and vapor compositions above, ideal liquid solutions Derive the expression for vapor pressure depression (from Raoult's law) Calculate the osmotic pressure of ionic and nonionic solutions Sketch and/or analyze (both p vs X and T vs X versions of) a two-component liquid-liquid phase diagram Sketch and/or analyze a two-component, liquid-solid phase diagram Identify solid solutions, compound formation, and incongruent melting points in phase diagrams Construct cooling curves from a phase diagram and vice versa

Define a suitable ± for an ionic compound in water solution

Find the expression for asalt for ionic solutions in terms of molality and ± Calculate the ionic strength of an ionic solution

Use the Debye-Hückel limiting law to calculate ± for an ionic compound in solution Write the cell reaction from the diagram of the cell and vice versa Calculate E o and E for an electrochemical cell Use a table of half-cell reduction potentials o o Calculate rG or rG from E or E for an electrochemical cell reaction and vice versa Find the equilibrium constant for an electrochemical cell reaction from E o o o Find rS and rH for an electrochemical cell reaction given E(T) Analyze a concentration cell

3. You should understand: The third law of thermodynamics and why it is important The meaning and utility of chemical potential The meaning and utility of activity and activity coefficient What is meant by components, phases and degrees of freedom (variance) Vapor pressure The origin of the Gibbs phase rule The triple point, critical point, vapor pressure curve, sublimation curve, and melting curve Vapor pressure depression, melting point depression, and boiling point elevation How fractional distillation works What the symbols  and || mean in electrochemical cell notation The notation and conventions for electrochemical cells What a liquid junction is The function of a salt bridge