Internal energy and energy transfers Flashcards
What is the internal energy of a substances?
- The energy stored by the particles.
- The sum of the total kinetic and potential energies that make up the system.
How does the 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 2 things can heating a substance do?
- Raise its temperature.
- Change the state of the substance.
What 3 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
ΔE = m c Δθ
Energy (J), mass (kg), specific heat capacity (J/kg/°C), temperature (°C).
Define specific heat capacity
The amount of energy needed to increase the temperature of a 1kg object/substances by 1°C.
Describe how the internal energy and temperature of a substance when a change of state occurs
- The internal energy of the substance will be increased or decreased.
- The temperature of the substance will remain constant.
Define specific latent heat
The amount of energy needed to change the state of a 1kg object/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 the specific latent heat of fusion?
The energy required to change 1kg of a substance from 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 liquid state to gas state without a change in temperature.
