Energy Absorbed During Phase Change
The specific term for energy absorbed or released during a phase transition (change of state) occurring at a constant temperature is latent heat.
Defining Latent Heat
When a substance changes its state, for example, from solid to liquid (melting) or liquid to gas (boiling), the energy it absorbs or releases is used to break or form intermolecular bonds, rather than increasing the substance's temperature.
- Latent Heat: This is the heat energy absorbed or released per unit mass during a change of state at a constant temperature and pressure.
- Kinetic Energy: This relates to the energy of motion of particles. It's a component of internal energy but not the term for the absorbed heat during a phase change.
- Thermal Energy: This is the total internal energy of a system related to temperature. It increases when temperature rises, but during a phase change, it remains constant.
- Specific Heat: This is the heat required to raise the temperature of a unit mass of a substance by one degree. It applies when temperature changes, not during a phase change at constant temperature.
Therefore, the energy absorbed during a change of state at constant temperature is correctly identified as latent heat.
Important Questions from Physics
What is the colour of the light emitted by the Sun?
Lightning occur in the sky when two clouds:
With reference to street-lighting, how do sodium lamps differ from LED lamps?
1. Sodium lamps produce light in 360 degrees but it is not so in the case of LED lamps.
2. As street lights, sodium lamps have a longer life span than LED lamps.
3. The spectrum of visible light from sodium lamps is almost monochromatic while LED lamps offer significant colour advantages in street lighting.
Select the correct answer using the code given below.
Which one of the following is a reason why astronomical distances are measured in light-years?
In a pressure cooker, the temperature at which the food is cooked depends mainly upon which of the following?
1. Area of the hole in the lid
2. Temperature of the flame
3. Weight of the lid
Select the correct answer using the code given below.
