P3 - Particle Model of Matter 2 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 ?
- Raising 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
Change in thermal energy (J) = mass (kg) x specific heat capacity (J/kg C) x temperature change ( C)
Define specific heat capacity
The amount of energy needed to increase the temperature of 1kg of a substance by 1°C.
Describe how the internal energy and temperature of a substance changes 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 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 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 ( vapour) without a change in temperature
