1.1C Energy and Changes of State

Energy added at a change of state goes into what and not into what?

goes into the breaking of inter-particle forces, not into raising the temperature

What happens in a-b?

solid is heated, vibrational energy of particles increases so the temperature increases

What happens in b-c?

Melting point, vibrations are energetic enough for particles to move away from fixed positions and form a liquid. Energy added breaks inter-particle forces, but does not raise kinetic energy so temperature remains constant

What happens in c-d?

liquid is heated, particles gain kinetic energy and temperature increases

What happens in d-e?

boiling point, sufficient energy to break all inter-particle forces and form a gas.

• Requires more energy than melting

• Temperature remains constant

• Bubbles of gas visible throughout volume of liquid

What happens in e-f?

gas is heated under pressure, kinetic energy of particles continues to rise, temperature also rises

What is the relationship between Celsius and Kelvin

Temperature (K) = Temperature (°C) - 273.15