P1.2 Heat And Temp Flashcards
Solid –> gas
Sublimation
Gas –> solid
Deposition
Liquid –> gas
Gas —> liquid
Evaporation
Condensation
KE energy in solids?
Not much energy so they only vibrate around their fixed positions
What happens when you heat a liquid?
Extra energy is passed into particles’ kinetic energy stores making them move faster. When the particles have enough energy to overcome the forces of attraction, big bubbles of gas form in the liquid. This is known as boiling.
What happens when you heat a solid?
The extra thermal energy makes particles vibrate faster until forces of attraction are partly overcome and particles start to move around. This is known as melting.
Absolute zero?
0°C = 273 K
What is temperature?
A measure of average kinetic energy of particles in a substance
What is energy measured in
Joules (J)
What 3 things can heating do?
1) produce change of state
2) make chemical reactions occur
3) change energy stored within system to increase temperature
What is a physical change?
No new substances are made, particles are simply rearranged therefore they are reversible.
What is a chemical reaction?
Bonding of atoms, new substance made. Non-reversible.
Specific heat capacity equation
Change in thermal energy = mass x SHC x change in temperature
E= mc🔺temperature
What is specific heat capacity?
The energy required to raise the temperature of 1kg of a substance by 1°c and describes the energy to melt/freeze.
what does SHC tell you?
How resistant a material is to a change in temperature (low shc means low resistance)
Specific latent heat formula
Energy = mass x SLH
E = ml
SHC unit of measurement?
Jkg^-1
What is specific heat capacity?
The energy required to change the state of 1kg of a substance without a change in temperature and describes the energy to boil or condense.
SHC vs SLH
Heat capacity = change of temperature
Latent heat = change of state
What happens if a substance is heated?
Internal energy increases
When does only ke change?
If a temperature change occurs during heating/cooling
When does only potential energy change?
If a state change occurs during heating/cooling because intermolecular bonds are weakened.
