Entropy and Free Energy
Chemical Thermodynamics
Chapter 19 Lecture Worksheet
Homework: 19.29, 19.31, 19.37, 19.39, 19.41, 19.43, 19.47, 19.51, 19.53a, 19.55, 19.61, 19.73, 19.75, 19.77
Recall from Chapter 5 - 1st Law of Thermodynamics o Energy is neither ____________________________________________. o Energy of the universe is constant. o Enthalpy Change ▪ Heat energy transferred at _____________________________________ ▪ Negative value = ▪ Positive value =
Spontaneous Processes - Thermodynamics o Tells us the _______________________________________ of a reaction ▪ Is the reaction ________________________? o Does NOT tell us the ________________ at which it happens. - Spontaneous change o One that proceeds to _________________ without outside ________________________ o If a reaction is ____________________ in one direction, it is _________________________ in the reverse direction. o ________________ will affect spontaneity - _____________________ reactions are typically thought to be _____________________. o Not always the case though! o Something else must be occurring
Entropy and the Second Law of Thermodynamics - Entropy o Symbol: S o Randomness or Disorder - Change in Entropy o Depends only on the initial and final values [state function]. o Symbol: ΔS = Sfinal – Sinitial - Second Law of Thermodynamics o The total entropy of the universe increases in any spontaneous process. o ΔSuniverse = ΔSsystem + ΔSsurroundings ▪ If ΔSuniverse is positive, then process is _____________________________ ▪ If ΔSuniverse is negative, then process _____________________________________ as written. ▪
Chapter 19 Lecture Worksheet
Homework: 19.29, 19.31, 19.37, 19.39, 19.41, 19.43, 19.47, 19.51, 19.53a, 19.55, 19.61, 19.73, 19.75, 19.77
Recall from Chapter 5 - 1st Law of Thermodynamics o Energy is neither ____________________________________________. o Energy of the universe is constant. o Enthalpy Change ▪ Heat energy transferred at _____________________________________ ▪ Negative value = ▪ Positive value =
Spontaneous Processes - Thermodynamics o Tells us the _______________________________________ of a reaction ▪ Is the reaction ________________________? o Does NOT tell us the ________________ at which it happens. - Spontaneous change o One that proceeds to _________________ without outside ________________________ o If a reaction is ____________________ in one direction, it is _________________________ in the reverse direction. o ________________ will affect spontaneity - _____________________ reactions are typically thought to be _____________________. o Not always the case though! o Something else must be occurring
Entropy and the Second Law of Thermodynamics - Entropy o Symbol: S o Randomness or Disorder - Change in Entropy o Depends only on the initial and final values [state function]. o Symbol: ΔS = Sfinal – Sinitial - Second Law of Thermodynamics o The total entropy of the universe increases in any spontaneous process. o ΔSuniverse = ΔSsystem + ΔSsurroundings ▪ If ΔSuniverse is positive, then process is _____________________________ ▪ If ΔSuniverse is negative, then process _____________________________________ as written. ▪