Ideal Gases + Thermal Physics Flashcards
What are the assumptions made in the Kinetic Theory of Gases.
The volume of molecules is negligible compared to the volume of the container.
Molecules do not attract each other.
Molecules move randomly.
All collisions (container and between molecules) are elastic.
The time taken for a collisions is far less than the time between collisions.
Any sample of an ideal gas contains a large number of molecules.
How can Absolute Zero be estimated?
On a graph of pressure/volume (y) against temperature, the x-intercept will be absolute zero since press/volume cannot be negative.
What is the Root Mean Square Speed?
The RMS speed is the mean of the squared velocities of a set of molecules rooted. This allows an understanding of the molecule’s movement excluding direction.
However, this is not the same as the mean speed for some reason.
Plot a graph of to show the distribution of molecule speeds with two different temperatures.
ADD IMAGE HERE.
What is the internal energy of a gas?
Internal Energy is the sum of the kinetic and potential energies of all the particles in a substance.
What is Thermal Equilibrium?
A state of a system in which there is no heat transfer between objects.
What is the Internal Energy of an Ideal Gas?
Since there are no electrostatic forces between molecules, there is no potential energy meaning that it is equal to the total kinetic energy.
What is Specific Heat Capacity?
The energy required to increase the temperature of 1kg of a substance by 1 degree.
What is Specific Latent Heat?
The energy required to change the state of 1kg of a substance.
Specific Latent Heat of Fusion refers to melting.
Specific Latent Heat of Vaporization refers to evaporation.
What does the viewing of smoke particles under a microscope tell us?
Air molecules move randomly and collide with smoke particles.
Smoke particles are visible, air molecules are not, therefore they are smaller.
Small movement of smoke particles is a result of collisions with air molecules on all sides.
Why does the temperature of the gas in a cylinder increase as a piston compresses it?
When a particle collides with the moving piston it rebounds with more energy than it had originally, this results in an increase of kinetic energy in the gas and hence an increase in temperature.
Describe how the kinetic and potential energies of a substance change as it is being heated and undergoing a state change.
As it is heated, both the kinetic and potential energies increase, as the state changes only the potential energy increases.
What is Boyle’s Law?
Boyle’s Law states that for a fixed mass of gas at a constant temperature: the pressure is inversely proportional to the volume.
How would you would find the SHC of a substance using the Method of Mixtures?
The method of mixtures uses two liquids both of known mass and temperature, one with a known SHC and one with an unknown SHC.
My mixing these liquids and measuring the final temperature the unknown SHC can be calculated.
