Thermal Flashcards
Internal Energy
The internal energy of a body is the sum of the randomly distributed kinetic and potential energies of all its molecules.
Specific Latent heat of fusion or vaporisation
The specific latent heat of fusion or vaporisation is the quantity of thermal energy required to change the state of 1kg of a substance without a change in temperature
The internal energy of an object is increased because…
Energy transfer by heating or work is done on the object (e.g by electricity)
The internal energy of an object stays constant when
No energy transfer is done on the object, energy transfer by heating and work done balance each other out.
The inversion tube experiment (what is it and the equation)
Lead spheres inside a tube, are inverted and spheres hit the bottom of the tube. The temperature is measured after n inversions.
c =gLn/T
c is the specific capacity of lead, g is gravity, L is the length of the tube, n is the number of inversions and T is the temperature change
the change of internal energy of the object =
the total energy transfer due to work done and heating
If a solid has a larger specific heat capacity than the liquid
the liquid heats up faster than the solid
The rise in temperature per second (T/t)
= P/mc
When a change of state occurs, what energy changes occurs
Kinetic energy stays the same, but potential energy increases as bonds are broken
Boyles Law
PV = constant
Charles law
V/T = constant
Pressure law
p/T = constant
Brownian motion
The erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium
What does Brownian motion show
the existence of molecules and atoms
Ideal gas
An ideal gas strictly obeys the equation of state
pV = nRT, (give some conditions of an ideal gas)
Heat is the
energy flow from a region at a higher temperature to a region at a lower temperature, due to the temperature difference
In an ideal gas, molecules of the gas are
identical
In an ideal gas, molecules exert no forces on each other except
during impact
In an ideal gas, the motion of molecules is
random
In an ideal gas, the time during collisions is
negligible compared to the time between collisions
In an ideal gas, what laws of physics are applied
Newtonian laws of physics
In an ideal gas, there is a large number
of particles
In an ideal gas, collisions are
elastic
The specific heat capacity of a substance is
the energy needed to raise the temperature of unit mass of the substance by 1k without change of state.
What are the two equations for moles calculations
N = n X Na
mass (in grams) = Mr x Moles
