Che Ch 18

• it will occur under a certain set of conditions
• ^ S universe is positive
• S sys + S surr = S universe

• the direct measure of the randomness or disorder of a system
• the larger the disorder, the larger the value of S
• S (solid) < S (liquid) << S (gas)

the absolute entropy of a substance at 1atm and 25 degrees C

the entropy of the universe increases in a spontaneous process and remains unchanged in an equilibrium process

• ^ Srxn = E nS (products) - E nS (reactants)
• don't forget to multiply by coefficents

• ^ S surr = - ^ H sys / T
• the higher the temperature is, the less the effect of the heat transfer on the entropy of the surroundings

• G = H - TS
• ^ G = ^ H - T ^ S
• negative G shifts to the right (spontaneous)

^ G = ^ G(standard) + RT In Q