Temperature and thermodynamics Flashcards
Thermal equilibrium?
Regions of equal temperature
Thermal energy?
Energy transferred from one object to another becaue of a temperature difference
How is temperature measured?
With physical properties
Examples of physical properties used to measure temperature
4
- density of a liquid- thermometer
- Volume of a gas at constant pressure, V∝t
- Resistance of a metal
- e.m.f of a thermouple
Thermodynamic temperature?
talk about scale
Uses a scale that is independant of the physical properties of any particular substance
Units of thermodynamic temperature
Kelvin
Fixed points of thermodynamic temperature scale
Absolute zero and triple point of pure water
What is absolute zero
Temperature at which no more energy can be removed from any body
zero ke and minimal pe
conversion from Celcius to Kelvin
+273.15
Specific heat capacity definition
The amount of energy required to increase the temperature of a 1kg mass of an object by 1K
Specific heat capacity formula
E= mcΔt
Specific latent heat def
Thermal energy required to change the state of 1kg of mass of an object without a change in temperature
Specific latent heat of fusion/ vaporisation
Fusion:
Thermal energy required to change the state from solid to liquid of 1kg of mass of an object without a change in temperature
Vaporisation:
Thermal energy required to change the state from liquid to gass of 1kg of mass of an object without a change in temperature
Specific latent heat formula
L= Q/m
Q=Lm
Internal energy def
This is the sum of random distribution of kinetic and potential energies associated with the molecules of a system
Internal energy can be determined by?
the state of a system
Kinetic energy determines what physical property
Temp
Potential energy determines what physical property
state
Formula for work done when volume of a gas changes
W=PΔV
-W?
Work is done by the gas, gas is expanding
+W?
Work is done on the gas, gas is being compressed
Requirement for thermal equilibrium
- two regions must be in contact
First law of thermodynamics?
U = Q+W
explains that energy is conserved
U is?
increase in internal energy
Q is?
Energy supplied by heating
W is?
Energy supplied doing work
Using the simple kinetic model of matter, describe the structure of a solid
3 points
- particles are very close together
- regular, repeating pattern
- vibrate about a fixed point
By reference to intermolecular forces
explain why the change in internal energy of an ideal
gas is equal to the change in total kinetic energy of its molecules.
2 marks
- in ideal gas, no intermolecular forces
- no potential energy
