Theme B Flashcards
Define thermal equilibrium
When there is no net heat flow between two objects.
State the zeroth law of thermodynamics
If two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other
Define temperature
The quantity which is equal between two objects in thermal equilibrium, such that heat spontaneously flows from high to low temperature.
Define internal energy
The sum of the total kinetic energy of the particles in a system and the total potential energy due to intermolecular forces, between the particles in the system.
What is heat according to kinetic theory
The transfer of internal energy between systems due to difference in tempuratures
What is temperature according to kinetic theory
A measurement of average internal kinetic energy of a system
Define conduction
Heat transfer through the contact forces
Define convection
Heat transfer via fluid between objects
Radiation
Heat transfer via electromagnetic radiation
State the formula relating thermal conductivity and heat:
Where:
∆Q = heat (J)
∆t = duration
k = thermal conductivity
A = cross-sectional area
∆T = different in temperature between the ends of the solid
∆x = width
Define heat capacity
The heat required to increase the temperature of a system by one unit
State the formula for specific heat capacity
Where:
Q = heat
m = mass
c = specific heat capacity
∆T = change in temperature
Define latent heat
Heat which doesn’t result in a temperature change as it is resulting in a phase change.
State the formula for specific latent heat.
Where:
Q = heat
m = mass
L = specific latent heat
Define pressure
Perpendicular force per unit area over the surface of the system.
State the formula for pressure
Where:
P = pressure
F = force
A = area
Base SI units for pressure
Pascal, Pa
Pa = N⋅m⁻²
What is the unified atomic mass unit
One twelfth of the mass of a carbon-12 atom
State the equation for moles
Where:
n = amount of moles
N = number of particles
Na = Avogadro constant
Define molar mass
Mass per mole of a molecule
List the assumptions of an ideal gas
- Volume of the molecules are negligible to the volume of the gas
- Newtons laws of motion apply
- There are only inter-molecular forces during collisions
- The duration of a collision is negligible to the duration between collisions
- The collisions of molecules with each other are elastic
- The molecules move in random directions with a range of speeds
List the conditions of ideal
gases
- Low pressure
- High temperature
- Low density
State the combined gas law
Where:
P = pressure
V = volume
T = temperature (KELVIN)
State Avogadro’s law
At constant pressure and temperature, the volume occupied by a gas is directly proportional the number of molecules in the gas.
