CHEM102 Lecture Notes - Standard Molar Entropy, Spontaneous Process, Boltzmann Equation

• School: University of Alberta
• Department: Chemistry
• Course: CHEM102
• Professor: Sai Yiu

Document Summary

Many chemical reactions or processes are spontaneous (occurs by itself without outside intervention): a ball rolls down a hill spontaneously but never rolls back up the hill, heat flows from hot object to cooler one. Iron rusts spontaneously as shown by the following chemical equation. 4fe (s) + 3o2 (g) 2fe2o3 (s) But iron oxide does not spontaneously change to iron metal and oxygen: methane burns to form carbon dioxide and water but the reversed reaction is not spontaneous. Ch4 (g) + 2o2 (g) co2 (g) + 2h2o (l: below 0oc, water spontaneously freezes and at temperatures above 0oc, ice melts spontaneously. The first law of thermodynamics is good for bookkeeping of energy in chemical reactions such as: how much energy is involved in the chemical reaction, does energy flow in or out of the system. The first law of thermodynamics does not make sense as to the direction of a reaction.