Thermodynamics Flashcards
absolute zero
lowest possible temperature kinetic energy = 0
How to convert from Celsius to Kelvin?
+273
thermometer
device that has volume that changes in a predictable way as temperature changes
What does a thermometer measure?
temperature of body it is in contact with
thermal interaction
energy transferred until two bodies have same temperature
thermal equilibrium
two bodies have same temperature
heat
energy that is transferred from one body to another as a result of a difference in termperature
internal energy
total random kinetic energy of particles + total inter-particle potential energy of particles
How can internal energy of a system change?
as result of heat added or taken out as result of work performed
specific heat capacity
energy required to increase temperature of a unit mass of a body be one kelvin
specific latent heat
amount of energy required to change the phase of a unit mass at constant temperature
Why is specific latent heat larger for vaporization than for melting?
increase in separation of molecules much larger when vaporizing more energy required to achieve greater separation
method of mixtures
measures specific heat capacity of a solid solid put into container of hot water reaches constant temperature temperature recorded solid transferred to calorimeter of known specific heat capacity and initial temperature final temperature of water recorded after thermal equilibrium reached
flaw with method of mixtures
likely that solid loses heat to surrounding air during transfer temperature of solid less than expected specific heat capacity appears larger
mole
contains as many particles as are atoms in 12g of carbon-12
Avogadro’s constant
number of particles in mole 6 x 10^23
atomic mass unit
1/12 mass of one atom of carbon-12
molar mass
sum of atomic masses of atoms
pressure
normal force applied per unit area
How do you calculate pressure at an angle?
P = Fcos/A
ideal gas characteristics
- point particles
- negligible volume
- no forces between molecules except when collide
- duration of collision negligible compared to time between collisions
- collisions are elastic
- molecules have range of speeds and move randomly
When can a real gas be approximated by an ideal gas?
when density low
pressure-volume law
P proportional to 1/V PV = constant
What is pressure-volume law also called?
Boyle’s law
How do you confirm the pV=constant relationship is constant?
take three points form graph and show product is same
volume-temperature law
V proportional to T V/T = constant
What is volume-temperature law also called?
Charles’ law
pressure-temperature law
P proportional to T P/T = constant
What is pressure-temperature law also called?
Gay-Lussac’s law Amontons’ law
equation of state of an ideal gas
pV = nRT
What is the Boltzmann equation?
Ek = 3/2kT
Boltzmann constant
R/NA
