Chemical Thermodynamics Chemistry, The Central Science, 11th edition Theodore L. Brown, H. Eugene LeMay, Jr., Bruce E. Bursten, and Catherine J. Murphy Chapter 19 Chemical Thermodynamics Dana & Michelle Chatellier University of Delaware © Copyright 2009, Pearson Education
The first law of thermodynamics states that __________ is conserved. matter energy entropy temperature
The first law of thermodynamics states that __________ is conserved. matter energy entropy temperature
Which process is NOT spontaneous at 25 °C? the melting of an ice cube the sublimation of dry ice the boiling of liquid nitrogen the freezing of ethyl alcohol
Which process is NOT spontaneous at 25 °C? the melting of an ice cube the sublimation of dry ice the boiling of liquid nitrogen the freezing of ethyl alcohol
Entropy is a measure of the __________ of a system. randomness internal energy temperature polarity
Entropy is a measure of the __________ of a system. randomness internal energy temperature polarity
Since entropy is a state function, the change in entropy is equal to its final value __________ its initial value. plus minus multiplied by divided by
Since entropy is a state function, the change in entropy is equal to its final value __________ its initial value. plus minus multiplied by divided by
Boltzmann’s constant = k. The number of microstates = W. Entropy = S Boltzmann’s constant = k. The number of microstates = W. Entropy = S. Which is correct? S = k x W S = k / W S = k ln W S = kW
Boltzmann’s constant = k. The number of microstates = W. Entropy = S Boltzmann’s constant = k. The number of microstates = W. Entropy = S. Which is correct? S = k x W S = k / W S = k ln W S = kW
Entropy decreases when: gases are formed from liquids. liquids are formed from solids. solids are formed from gases. the number of gas molecules increases during a chemical reaction.
Entropy decreases when: gases are formed from liquids. liquids are formed from solids. solids are formed from gases. the number of gas molecules increases during a chemical reaction.
The second law of thermodynamics states that entropy __________ as a result of an irreversible process. increases decreases remains unchanged reaches equilibrium
The second law of thermodynamics states that entropy __________ as a result of an irreversible process. increases decreases remains unchanged reaches equilibrium
The third law of thermodynamics states that the entropy of a pure, perfect crystalline substance at absolute zero (0 K) is: infinite. increasing. decreasing. zero.
The third law of thermodynamics states that the entropy of a pure, perfect crystalline substance at absolute zero (0 K) is: infinite. increasing. decreasing. zero.
H = enthalpy. S = entropy. T = Kelvin temperature H = enthalpy. S = entropy. T = Kelvin temperature. The Gibbs free energy, G, is: H + TS H – TS H x TS H / TS
H = enthalpy. S = entropy. T = Kelvin temperature H = enthalpy. S = entropy. T = Kelvin temperature. The Gibbs free energy, G, is: H + TS H – TS H x TS H / TS
The value of ∆G, the Gibbs free energy change, for a system at equilibrium is: positive. negative. rapidly fluctuating from positive to negative. zero.
The value of ∆G, the Gibbs free energy change, for a system at equilibrium is: positive. negative. rapidly fluctuating from positive to negative. zero.