Chemistry 1027A/B Lecture Notes - Lecture 7: Standard Molar Entropy, Ice Cube, Spontaneous Process
15 Mar 2015
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Document Summary
For a process where no work has been done (w=0) e= h. Esys or hsys not the only criterion needed for a reaction to occur spontaneously. Ice cube (system) placed on a warm brick (surroundings) will melt. Thermal energy provided by the brick disrupts intermolecular forces that hold the ice together solid liquid. Lowers temperature of brick such that the overall energy of the system and surroundings is conserved. Obeys first law - occurs spontaneously: reverse process. Sample of liquid water is placed on the same brick. Both water and brick are at the initial temperature of 15 c. Brick would not absorb heat from the water thereby cooling water into ice. Measure of randomness or the disorder of a system. Higher the number of possible arrangements for system greater entropy. Spontaneity is not related to reaction rate. S depends only on entropies of initial and final state (state function)
