CHEM 120 Lecture Notes - Lecture 4: Calorimetry, Chemical Energy, James Prescott Joule

• School: McGill University
• Department: Chemistry
• Course: CHEM 120
• Professor: Laura Pavelka

Document Summary

Chem 120 lecture 4 thermodynamics & thermochemistry. Thermodynamics concerns itself with energy; ie. the conversion of heat to mechanical work (and vise versa), and its relationship to the large scale bulk properties of a system that are measurable: v, t, p, heat capacity, density, etc . Thermodynamics describes the behavior of matter and the transformation between different forms of energy on a macroscopic scale (ie. large collections of molecules, not individual molecules) Thermochemistry is a branch of thermodynamics that investigates the flow of energy stored in chemical bonds (amongst other things) **** products of a chemical reaction are not the only new molecules that are formed. Energy can also be released or consumed; the most important/ salient feature of many reactions **** Example: the combustion of hydrocarbons: (general equation) : cxhy + (x + y/4)o2 xco2 + (y/2)h2o + heat ( release of energy!) Energy can be exchanged in surroundings through heat and work.