Thermodynamics Flashcards
What is statistical thermodynamics?
The unification of macroscopic and microscopic approaches.
What is an open system?
A system that can exchange both matter and energy with its surroundings.
What is a closed system?
A system that can exchange energy but not matter with its surroundings.
What is an isolated system?
A system that can’t exchange matter nor energy with its surroundings.
What is the symbol for heat?
q
What is heat?
Energy dispersed as random motion.
What is the symbol for work?
w
What is work?
Energy dispersed as non-random motion.
What is the -1st law?
Heat travels from hot to cold.
What is the zero law?
If the bodies A and B and B and C are in thermal equilibrium then A and C are in thermal equilibrium.
What is the symbol for internal energy?
U
What is internal energy?
The total energy contained within a system.
What happens to the system if the internal energy system is less than zero?
Energy is lost from the system.
What happens to the system if the internal energy change is greater than zero?
Energy is gained from the system.
What is the 1st law of thermodynamics?
The internal energy of an isolated system is constant.
What is the symbol for enthalpy?
H
What kind of process has occurred if enthalpy is less than zero?
An exothermic process.
What kind of process has occurred if the enthalpy is greater than zero?
An endothermic process.
What is a spontaneous change?
One that doesn’t require input of energy.
What is a non-spontaneous change?
A change that requires work in order to be brought about.
What is the symbol for entropy?
S
What is the second law of thermodynamics?
The entropy of an isolated system increases for any spontaneous change.
What does the thermodynamic equilibrium represent?
The natural tendency for things to fall to a lower energy.
What is the third law of thermodynamics?
The entropy of a perfect crystal at absolute zero of the temperature scale is zero.
What is standard molar entropy?
The entropy in one mole of a substance under standard conditions.
What is standard free energy change?
The value of dG when reactants in their standard states are converted to products in their standard states.
What is the free energy of formation?
The free energy change when a compound in its standard sate is prepared from its elements in their standard states.
What is the reaction quotient (Q)?
It defines reactants and products concentrations ratio at any stage of the chemical transformation.
What is the equilibrium constant?
The value of the reaction quotient at equilibrium.
