Thermal Physics And Gas Laws Flashcards
(25 cards)
Specific heat capacity
The energy needed to raise the temperature of 1kg of the material by 1 degree without it changing state. It is measured in J/kg (degree C)
Latent heat
The energy transfered during a change if state without changing temperature.
Specific latent heat
The energy required to change the state of 1kg of a material without changing temperature
Specific latent heat of fusion
Specific latent heat of changing a material from solid to liquid
Specific latent heat of vaporisation
The specific latent heat of changing a material from a liquid to a gas
Pressure law
Pressure it proportional to temp when volume and mass is fixed
N represents
number of molecules
n represents
no of moles
The number of particles in a substance (N)
N = n(mole)*N(avogadros constant)
The mass of a substance (M)
M=n*M(molar mass)
Molecular mass of a substance (m)
m=M(molar mass)/N(avogadros constant)
Charles’s Law
Fixed:
-Pressure
-Mass
Relationship:
Volume is proportional to temperature.
Boyle’s Law
Fixed:
-Temperature
-Mass
Relationship:
Volume is inversely proportional to pressure.
Avogadro’s Law
Fixed:
-Temperature
-Pressure
Relationship:
Volume is proportional to n (mole no)
What does Avogadro’s law tell us?
that 1mole of any gas occupies roughly the same volume as 1 mole of any other gas.
Ideal gases (perfect/not realistic)
Do not change state
Particle occupy negligible volume
There are no intermolecular forces between the particles.
Collisions between particles are elastic.
Area of p-V graphs
work done
Gas expansion
Work done by the gas.
change in volume is +
Work done by gas is +
Work done on gas is -
Gas is compressed
Work done on the gas.
Change in volume is -
work done by gas is -
work done on gas is +
When observing smoke particles under a microscope, they are observed to move in a random way. What conclusions can be drawn about air molecules and their motion resulting from this observation?
The air molecules are much smaller than the smoke particles.
The motion if the aur molecules is random.
Brownian motion
We can observe Brownian motion in smoke particles. Brownian motion is explained by air molecules moving at random and knocking into smoke particles. This provides evidence of the random motion of air molecules, which is one of the assumptions of the kinetic theory of gases.
The ideal gas equation
We can derive the ideal gas equation from the kinetic theory equation. The ideal gas equation is based on experiments, so provides experimental support for the kinetic theory of gases.
Absolute zero is the temperature…
of particles with the minimum possible kinetic energy.
The ideal gas laws are empirical laws. This means that they are…
based on observations and experiments.
