P1.2 Changes of State

• Latent heat is the energy absorbed or released during a change of state without a change in temperature
• State diagrams illustrate phase transitions under different conditions.


  True
• In a liquid, particles are closely packed but can move around each other
• Endothermic changes of state absorb energy from the surroundings
• Match the change of state with its type of energy change.

  Boiling ↔️ Endothermic

  Freezing ↔️ Exothermic
• Match the type of latent heat with its process.

  Latent heat of fusion ↔️ Melting/Freezing

  Latent heat of vaporization ↔️ Boiling/Condensation
• Changes of state involve transitions between solid, liquid, and gas
• Order the types of latent heat based on the state transition they involve.

  1️⃣ Latent heat of fusion

  2️⃣ Latent heat of vaporization
• Match the property with the state of matter.

  Fixed shape ↔️ Solid

  Takes the shape of the container ↔️ Liquid

  Expands to fill the container ↔️ Gas
• A gas has a fixed volume.

  False
• Exothermic changes of state release energy to the surroundings
• Latent heat is the energy absorbed or released during a change of state without a change in temperature
• Order the changes of state based on whether they are endothermic or exothermic.

  1️⃣ Endothermic: Melting

  2️⃣ Endothermic: Boiling

  3️⃣ Exothermic: Condensation

  4️⃣ Exothermic: Freezing
• What is latent heat defined as?

  Energy during state change
• Latent heat of vaporization changes liquids to gases.

  True
• Match the property with the state of matter:

  Fixed shape ↔️ Solid

  Fixed volume ↔️ Liquid

  Random motion of particles ↔️ Gas
• Endothermic changes absorb energy from the surroundings.
• Exothermic changes release energy to the surroundings.


  True
• Match the change of state with its energy change type:

  Melting ↔️ Endothermic

  Condensation ↔️ Exothermic
• What are the two types of latent heat?

  Fusion and vaporization
• Latent heat of vaporization is needed to change a liquid into a gas.
• What is latent heat of vaporization?

  Energy to change liquid to gas
• Latent heat of vaporization is released during condensation.

  True
• What is latent heat of fusion?

  Energy to change solid to liquid
• Latent heat of fusion is released during freezing.

  True
• Latent heat is the energy absorbed or released during a change of state
• Order the main phase transitions based on energy change (from exothermic to endothermic):

  1️⃣ Freezing

  2️⃣ Condensation

  3️⃣ Boiling

  4️⃣ Melting
• What do state diagrams visually depict?

  Phase transitions and conditions
• In the exothermic processes of condensation and freezing, heat energy is released to the surroundings
• Latent heat of fusion changes solids to liquids.
• What are changes of state affected by?

  Temperature and pressure
• What are the two types of energy changes involved in changes of state?

  Endothermic and exothermic
• What are two examples of endothermic processes?

  Melting and boiling
• What are two examples of exothermic processes?

  Freezing and condensation
• Latent heat is absorbed or released during a change of state without a change in temperature.


  True
• What does latent heat of fusion overcome during melting?

  Intermolecular forces
• Match the latent heat type with its process:

  Fusion ↔️ Melting or freezing

  Vaporization ↔️ Boiling or condensation
• During boiling, the liquid absorbs latent heat from the surroundings
• During melting, the solid absorbs latent heat from the surroundings
• Match the type of latent heat with its process:

  Latent heat of fusion ↔️ Melting/Freezing

  Latent heat of vaporization ↔️ Boiling/Condensation