Topic 3- Internal energy and energy transfers Flashcards
What is the internal energy of a substance?
The energy stored by the particles
The sum of the total kinetic and potential energies that make up the system
How does heating affect the energy of a substance?
Heating transfers energy to the substance
It increases the energy of the particles that make up the substance
What two things can heating a substance do?
- Raise its temperature
- Change the state of the substance
What three factors determine the temperature change of a system?
- Mass of substance being heated
- Type of material (specific heat capacity)
- Energy inputted into the system
State the equation used to calculate the temperature change when a substance is heated. Give appropriate units
- Q=mc\ T
Energy (J), Mass (kg), specific heat capacity (J/kg/degree C), temperature (degree Celsius)
Define specific heat capacity
The amount of energy needed to increase the temperature of 1 kg of a substance by 1 degree celcius
Describe how internal energy and temperature of a substance changes when a change of state occurs
The internal energy of the substance will decrease or increase
The temperature of the substance will remain constant
Define specific latent heat
The amount of energy needed to change the state of 1kg of a substance with no change in temperature
State the equation for the energy required to change state. Give appropriate units
Energy to change state= mass x specific latent heat
energy (j) mass (kg) specific latent heat (J/kg)
What is specific latent heat of fusion?
The energy required to change 1kg of a substance from a solid state to liquid state without a change in temperature
What is the specific latent heat of vaporisation?
the energy required to change 1kg of a substance from a liquid state to gas state (vapour) without a change in temperature
