CHEM 001B Lecture Notes - Lecture 23: Standard Molar Entropy, Boltzmann Equation, Thermodynamics
Document Summary
A measure of how dispersed the energy in a system is at a specific. Energy distribution is affected by molecular motion and volume. Different molecular states related to molecular motion are separated by specific energies. A unique distribution of particles among energy levels. K b = boltzmann constant (1. 38 x 10 -23 j/k) = r/n a. Entropy increases as the number of microstates increases. The entropy of a perfect crystal is zero at absolute zero. Provides a point of reference or baseline for entropy. The absolute entropy of 1 mol of a substance in its standard state at 298 k and 1 bar (~1 atm) of pressure. Calculated from measurement of molar heat capacities as a function of temperature. Rotational : spinning motion around axis perpendicular to bond. Vibrational : movement of atoms toward/ away from each other. As temperature increases, amount of motion increases. Entropy increases as the complexity of molecular structure increases.
