Introduction Flashcards
What is thermodynamics concerned with?
Conservation of energy
Transfer of energy (via work or heat)
What does thermodynamics predict?
Spontaneous direction of chemical processes
The equilibrium states of chemical systems
What does chemical kinetics concern?
The rate of processes of chemical systems
What are the two form of energy thermodynamics is concerned with?
Heat and work
What is heat?
The transfer of energy due to a difference in temperature
Transfer due to chaotic, disorganized motion
What is work>
A process which can be used directly to move an object to a certain distance
Transfer due to organized motion of particles
Formula for work
w = { F. ds
Integration of force with respect to displacement
What is a system?
A region of chemical interest
What are surroundings?
The rest of the universe, the region outside the system.
Separated by a boundary
What are the different systems?
Open system
Isolated system
Closed system (adiabatic and diathermic)
What is an open system?
Both energy and matter can be freely exchanged
What is an isolated system?
Neither energy not matter can be exchanged
What is an adiabatic system?
Only work can be exchanged
What is a diathermic system?
Only heat exchanged
Define exothermic
The system gives out heat
Define endothermic
The system takes in heat
Define exergonic
The system gives out energy
Define endergonic
The system takes in energy
What is the sign convention?
Energy taken in by the system is positive
Energy given out is negative
What is the zeroth law of thermodynamics?
There is a unique scale of temperature
Measured in Kelvin (K)
At 0K, the energy of a particle is 0
If body A is in thermal equilibrium with body B, and B with C, then A is also in thermal equilibrium with C
What is the first law of thermodynamics?
The energy of an isolated system is constant
Energy cannot be created not destroyed, only transferred
What is the second law of thermodynamics?
When two systems are brought into thermal contact, heat flows spontaneously from the one at the higher temperature to the one at the lower temperature
This process is determined by changes in entropy
Heat cannot be completely converted to work for a cyclic process but work can be spontaneously converted to heat
Spontaneous changes are always accompanied by a conversion of energy into a more disordered form
The entropy increases during any spontaneous change or process
What is the third law of thermodynamics?
All perfect materials have the same entropy at absolute 0
You can’t win, you can only break even
You can only break even when it is very cold
It never gets that cold
Define physical state
The condition of a sample of stuff in terms of physical form
Define force
A body travels in a straight line at constant speed unless acted on by a force
Define work
The product of force and distance
Define pressure
Force per unit area
Define temperature
Property that determines direction of energy flow
Define volyme
The space occupied by a system
Define energy
Capacity to do work
Define mass
Amount of stuff, independent of identity
Define molar mass
Mass per mole of substance
Define RMM
Relative molecular mass is the atomic or molecular mas relative to carbon-12
Define concentration
The amount of solute per unit volume of solution
What is an extensive property
Dependent on amount e.g. mass, volume
What is an intensive property?
Independent of amount
