4. Temperature Flashcards
Define thermal energy:
The energy possessed by an object due to its temperature
Define temperature:
Temperature is a measure of the average kinetic energy of the particles in a substance
How is thermal energy transferred?
It is transferred from a region of higher temperature to a region of lower temperature and energy will continue to be transferred until both regions are the same temperature
What is a thermometer?
A thermometer is any device that uses a physical quantity that varies with temperature to measure temperature
List the physical quantities that vary with temperature:
- Th density of a liquid
- The volume of a gas at constant pressure
- Resistance of metal
- EMF of a thermocouple
At what two points are thermometers calibrated to?
0 and 100 or melting and boiling point
Define specific heat capacity:
The amount of thermal energy required to raise the temperature of 1kg of a substance by 1°C
What is the specific heat capacity equation?
ΔQ = mcΔθ
ΔQ = change in thermal energy in J
m = mass of the substance you are heating up in kg
c = specific heat capacity of the substance in Jkg-1K-1or Jkg-1 °C-1
Δθ = change in temperature in K or °C
Define specific latent heat:
The thermal energy required to change the state of 1kg of mass of a substance without any change in temperature
State the difference between SLH of fusion vs vaporisation:
SLH of fusion = is the heat energy required to convert a solid into a liquid at its melting point
SLH of vaporisation = is the heat energy required to convert a liquid into a gas at its boiling point
What is the equation for specific latent heat?
Q = Lm
Q = amount of thermal energy to change the state in J
L = latent heat of fusion or vaporisation in Jkg-1
m = mass of the substance changing state in kg
What is the specific heat capacity of water?
Specific heat capacity = 4200 Jkg-1K-1or Jkg-1 °C-1
What are the specific latent heat values of water?
Specific latent heat of fusion = 330 kJkg-1
Specific latent heat of vaporisation = 2.26 MJkg-1
