AP Chemistry Flashcards: Energy Of Phase Changes

What this deck covers

This deck focuses on Energy Of Phase Changes, giving you a quick way to review the definitions, rules, and examples that matter most for AP Chemistry.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is the heat change when 1 mole of gas becomes a liquid?

Answer: Molar heat of condensation. Energy released per mole when gas becomes liquid.

Flashcard 2: What is the phase change from gas to liquid called?

Answer: Condensation. Phase transition from gaseous to liquid state.

Flashcard 3: What is the energy change associated with the phase change of freezing?

Answer: Latent heat of fusion. Freezing involves the same energy as fusion but opposite direction.

Flashcard 4: What is the heat change when 1 mole of gas becomes a liquid?

Answer: Molar heat of condensation. Energy released per mole when gas becomes liquid.

Flashcard 5: What is the term for the heat change when 1 mole of a solid becomes a liquid?

Answer: Molar heat of fusion. Energy change per mole for solid-to-liquid transition.

Flashcard 6: What is the unit of molar heat of fusion in SI units?

Answer: Joules per mole ($\text{J/mol}$). Standard unit expressing energy per mole for fusion.

Flashcard 7: What is the formula for calculating the heat required for a phase change?

Answer: $q = m \times \text{ΔH}$. Where $q$ is heat, $m$ is mass, and $\text{ΔH}$ is enthalpy change.

Flashcard 8: What is the phase change from gas directly to solid called?

Answer: Deposition. Direct phase transition from gas to solid state.

Flashcard 9: What does the symbol $c$ represent in the formula $q = m \times c \times \text{ΔT}$?

Answer: Specific heat capacity. Energy required to raise temperature per unit mass per degree.

Flashcard 10: What is the phase change from solid directly to gas called?

Answer: Sublimation. Direct transition from solid to gas without liquid phase.

Flashcard 11: What does the symbol $m$ represent in the heat equations?

Answer: Mass of the substance. Mass is a key variable in all heat transfer calculations.

Flashcard 12: What is the formula for calculating the heat required for a phase change?

Answer: $q = m \times \text{ΔH}$. Where $q$ is heat, $m$ is mass, and $\text{ΔH}$ is enthalpy change.

Flashcard 13: What is the enthalpy change for the transition from liquid to solid?

Answer: $-\text{ΔH}_{\text{fusion}}$. Freezing releases energy, opposite sign of fusion.

Flashcard 14: What is the heat change when 1 mole of gas becomes a liquid?

Answer: Molar heat of condensation. Energy released per mole when gas becomes liquid.

Flashcard 15: What is the term for the energy change when a liquid turns to gas without temperature change?

Answer: Latent heat of vaporization. Energy change for liquid-to-gas transition at constant temperature.

Flashcard 16: What is the energy change for converting 1 mole of solid directly to gas?

Answer: Molar heat of sublimation. Energy per mole for direct solid-to-gas transition.

Flashcard 17: Calculate the heat absorbed by 25g of ice melting, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 8,350 J. $q = 25\text{g} \times 334\text{J/g} = 8,350\text{J}$

Flashcard 18: What is the phase change from gas directly to solid called?

Answer: Deposition. Direct phase transition from gas to solid state.

Flashcard 19: What does the symbol $c$ represent in the formula $q = m \times c \times \text{ΔT}$?

Answer: Specific heat capacity. Energy required to raise temperature per unit mass per degree.

Flashcard 20: What is the energy change for converting 1 mole of solid directly to gas?

Answer: Molar heat of sublimation. Energy per mole for direct solid-to-gas transition.

Flashcard 21: What is the typical unit for specific heat capacity?

Answer: Joules per gram per degree Celsius ($\text{J/g°C}$). Standard unit for energy per mass per temperature change.

Flashcard 22: What is the term for the heat change when 1 mole of a liquid becomes a gas?

Answer: Molar heat of vaporization. Energy change per mole for liquid-to-gas transition.

Flashcard 23: What is the energy change associated with the phase change of freezing?

Answer: Latent heat of fusion. Freezing involves the same energy as fusion but opposite direction.

Flashcard 24: What is the term for the heat change when 1 mole of a solid becomes a liquid?

Answer: Molar heat of fusion. Energy change per mole for solid-to-liquid transition.

Flashcard 25: What is the term for the heat required to change 1 gram of a substance from solid to liquid?

Answer: Latent heat of fusion. Specific energy required for the melting process per gram.

Flashcard 26: What is the term for the heat required to convert 1 gram of a solid to a gas?

Answer: Latent heat of sublimation. Energy for direct solid-to-gas transition per unit mass.

Flashcard 27: Find the heat released by 60g of steam condensing, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 135,600 J. $q = 60\text{g} \times 2260\text{J/g} = 135,600\text{J}$

Flashcard 28: What is the term for the energy change when a liquid turns to gas without temperature change?

Answer: Latent heat of vaporization. Energy change for liquid-to-gas transition at constant temperature.

Flashcard 29: Find the heat released by 60g of steam condensing, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 135,600 J. $q = 60\text{g} \times 2260\text{J/g} = 135,600\text{J}$

Flashcard 30: What is the phase change from liquid to solid called?

Answer: Freezing. Phase transition from liquid to solid state.

Flashcard 31: What is the unit of latent heat of fusion in the SI system?

Answer: Joules per gram ($\text{J/g}$). Standard unit expressing energy per unit mass for fusion.

Flashcard 32: What does the symbol $q$ represent in the context of phase changes?

Answer: Heat energy. Represents the thermal energy transferred during phase transitions.

Flashcard 33: What is the phase change from solid directly to gas called?

Answer: Sublimation. Direct transition from solid to gas without liquid phase.

Flashcard 34: What is the typical unit for specific heat capacity?

Answer: Joules per gram per degree Celsius ($\text{J/g°C}$). Standard unit for energy per mass per temperature change.

Flashcard 35: Calculate the heat absorbed by 25g of ice melting, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 8,350 J. $q = 25\text{g} \times 334\text{J/g} = 8,350\text{J}$

Flashcard 36: What is the unit of molar heat of fusion in SI units?

Answer: Joules per mole ($\text{J/mol}$). Standard unit expressing energy per mole for fusion.

Flashcard 37: What is the energy change for converting 1 mole of solid directly to gas?

Answer: Molar heat of sublimation. Energy per mole for direct solid-to-gas transition.

Flashcard 38: Find the heat released by 60g of steam condensing, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 135,600 J. $q = 60\text{g} \times 2260\text{J/g} = 135,600\text{J}$

Flashcard 39: What is the phase change from solid to liquid called?

Answer: Melting. Phase transition from solid to liquid state.

Flashcard 40: What is the formula for calculating heat when temperature changes?

Answer: $q = m \times c \times \text{ΔT}$. Used for heating or cooling without phase change.

Flashcard 41: What is the formula for calculating heat when temperature changes?

Answer: $q = m \times c \times \text{ΔT}$. Used for heating or cooling without phase change.

Flashcard 42: What is the unit of latent heat of fusion in the SI system?

Answer: Joules per gram ($\text{J/g}$). Standard unit expressing energy per unit mass for fusion.

Flashcard 43: State the formula for calculating heat during a temperature change.

Answer: $q = m \times c \times \text{ΔT}$. Where $c$ is specific heat capacity and $\text{ΔT}$ is temperature change.

Flashcard 44: What does the symbol $q$ represent in the context of phase changes?

Answer: Heat energy. Represents the thermal energy transferred during phase transitions.

Flashcard 45: What phase change is associated with the latent heat of fusion?

Answer: Solid to liquid. Fusion refers to the melting process from solid to liquid.

Flashcard 46: What does the symbol $q$ represent in the context of phase changes?

Answer: Heat energy. Represents the thermal energy transferred during phase transitions.

Flashcard 47: Determine the heat change for vaporization of 30g of water, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 67,800 J. $q = 30\text{g} \times 2260\text{J/g} = 67,800\text{J}$

Flashcard 48: Identify the phase change for the latent heat of vaporization.

Answer: Liquid to gas. Vaporization specifically describes the liquid-to-gas transition.

Flashcard 49: Identify the phase change for the latent heat of vaporization.

Answer: Liquid to gas. Vaporization specifically describes the liquid-to-gas transition.

Flashcard 50: What is the formula for calculating heat when temperature changes?

Answer: $q = m \times c \times \text{ΔT}$. Used for heating or cooling without phase change.

Flashcard 51: What happens to the temperature of a substance during a phase change at constant pressure?

Answer: Remains constant. Energy goes into breaking bonds, not changing temperature.

Flashcard 52: Determine the heat change when a 20g ice cube melts, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 6,680 J. $q = 20\text{g} \times 334\text{J/g} = 6,680\text{J}$

Flashcard 53: Calculate the heat required to vaporize 100g of water, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 226,000 J. $q = 100\text{g} \times 2260\text{J/g} = 226,000\text{J}$

Flashcard 54: What is the energy change associated with the phase change of freezing?

Answer: Latent heat of fusion. Freezing involves the same energy as fusion but opposite direction.

Flashcard 55: What does the symbol $m$ represent in the heat equations?

Answer: Mass of the substance. Mass is a key variable in all heat transfer calculations.

Flashcard 56: Determine the heat change when a 20g ice cube melts, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 6,680 J. $q = 20\text{g} \times 334\text{J/g} = 6,680\text{J}$

Flashcard 57: Calculate the energy required to freeze 15g of water, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 5,010 J. $q = 15\text{g} \times 334\text{J/g} = 5,010\text{J}$

Flashcard 58: What is the phase change from solid directly to gas called?

Answer: Sublimation. Direct transition from solid to gas without liquid phase.

Flashcard 59: What does the symbol $m$ represent in the heat equations?

Answer: Mass of the substance. Mass is a key variable in all heat transfer calculations.

Flashcard 60: What is the phase change from solid directly to gas called?

Answer: Sublimation. Direct transition from solid to gas without liquid phase.

Flashcard 61: What is the phase change from solid to liquid called?

Answer: Melting. Phase transition from solid to liquid state.

Flashcard 62: Calculate the heat required to vaporize 100g of water, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 226,000 J. $q = 100\text{g} \times 2260\text{J/g} = 226,000\text{J}$

Flashcard 63: What is the term for the energy change when a liquid turns to gas without temperature change?

Answer: Latent heat of vaporization. Energy change for liquid-to-gas transition at constant temperature.

Flashcard 64: What does the symbol $\text{ΔH}$ represent in phase change calculations?

Answer: Enthalpy change. Represents the energy change per unit mass during phase transitions.

Flashcard 65: What happens to the temperature of a substance during a phase change at constant pressure?

Answer: Remains constant. Energy goes into breaking bonds, not changing temperature.

Flashcard 66: What does the symbol $\text{ΔH}$ represent in phase change calculations?

Answer: Enthalpy change. Represents the energy change per unit mass during phase transitions.

Flashcard 67: What is the phase change from gas directly to solid called?

Answer: Deposition. Direct phase transition from gas to solid state.

Flashcard 68: What is the term for the heat change when 1 mole of a solid becomes a liquid?

Answer: Molar heat of fusion. Energy change per mole for solid-to-liquid transition.

Flashcard 69: Calculate the heat required to vaporize 100g of water, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 226,000 J. $q = 100\text{g} \times 2260\text{J/g} = 226,000\text{J}$

Flashcard 70: State the formula for calculating heat during a temperature change.

Answer: $q = m \times c \times \text{ΔT}$. Where $c$ is specific heat capacity and $\text{ΔT}$ is temperature change.

Flashcard 71: What is the term for the heat change when 1 mole of a solid becomes a liquid?

Answer: Molar heat of fusion. Energy change per mole for solid-to-liquid transition.

Flashcard 72: What is the formula for calculating the heat required for a phase change?

Answer: $q = m \times \text{ΔH}$. Where $q$ is heat, $m$ is mass, and $\text{ΔH}$ is enthalpy change.

Flashcard 73: What is the typical unit for specific heat capacity?

Answer: Joules per gram per degree Celsius ($\text{J/g°C}$). Standard unit for energy per mass per temperature change.

Flashcard 74: What is the enthalpy change for the transition from liquid to solid?

Answer: $-\text{ΔH}_{\text{fusion}}$. Freezing releases energy, opposite sign of fusion.

Flashcard 75: What is the energy change associated with the phase change of freezing?

Answer: Latent heat of fusion. Freezing involves the same energy as fusion but opposite direction.

Flashcard 76: Calculate the energy required to freeze 15g of water, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 5,010 J. $q = 15\text{g} \times 334\text{J/g} = 5,010\text{J}$

Flashcard 77: What is the energy change associated with the phase change of deposition?

Answer: Latent heat of deposition. Energy released when gas transitions directly to solid.

Flashcard 78: What does the symbol $c$ represent in the formula $q = m \times c \times \text{ΔT}$?

Answer: Specific heat capacity. Energy required to raise temperature per unit mass per degree.

Flashcard 79: What is the term for the heat change when 1 mole of a liquid becomes a gas?

Answer: Molar heat of vaporization. Energy change per mole for liquid-to-gas transition.

Flashcard 80: What happens to the temperature of a substance during a phase change at constant pressure?

Answer: Remains constant. Energy goes into breaking bonds, not changing temperature.

Flashcard 81: What is the phase change from liquid to solid called?

Answer: Freezing. Phase transition from liquid to solid state.

Flashcard 82: Identify the phase change for the latent heat of vaporization.

Answer: Liquid to gas. Vaporization specifically describes the liquid-to-gas transition.

Flashcard 83: Calculate the heat released when 50g of steam condenses, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 113,000 J. $q = 50\text{g} \times 2260\text{J/g} = 113,000\text{J}$

Flashcard 84: What is the phase change called when a gas turns into a solid?

Answer: Deposition. Direct phase transition from gas to solid state.

Flashcard 85: Identify the phase change for the latent heat of vaporization.

Answer: Liquid to gas. Vaporization specifically describes the liquid-to-gas transition.

Flashcard 86: Calculate the heat required to melt 50g of ice, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 16,700 J. $q = 50\text{g} \times 334\text{J/g} = 16,700\text{J}$

Flashcard 87: What is the term for the heat required to change 1 gram of a substance from solid to liquid?

Answer: Latent heat of fusion. Specific energy required for the melting process per gram.

Flashcard 88: What is the term for the heat required to convert 1 gram of a solid to a gas?

Answer: Latent heat of sublimation. Energy for direct solid-to-gas transition per unit mass.

Flashcard 89: What does the symbol $\text{ΔH}$ represent in phase change calculations?

Answer: Enthalpy change. Represents the energy change per unit mass during phase transitions.

Flashcard 90: What is the phase change from gas to liquid called?

Answer: Condensation. Phase transition from gaseous to liquid state.

Flashcard 91: Calculate the heat required to melt 50g of ice, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 16,700 J. $q = 50\text{g} \times 334\text{J/g} = 16,700\text{J}$

Flashcard 92: State the formula for calculating heat during a temperature change.

Answer: $q = m \times c \times \text{ΔT}$. Where $c$ is specific heat capacity and $\text{ΔT}$ is temperature change.

Flashcard 93: What does the symbol $q$ represent in the context of phase changes?

Answer: Heat energy. Represents the thermal energy transferred during phase transitions.

Flashcard 94: What is the term for the energy change when a liquid turns to gas without temperature change?

Answer: Latent heat of vaporization. Energy change for liquid-to-gas transition at constant temperature.

Flashcard 95: What is the term for the heat required to convert 1 gram of a solid to a gas?

Answer: Latent heat of sublimation. Energy for direct solid-to-gas transition per unit mass.

Flashcard 96: Calculate the energy required to freeze 15g of water, given $\text{ΔH}_{\text{fusion}} = 334 \text{J/g}$.

Answer: 5,010 J. $q = 15\text{g} \times 334\text{J/g} = 5,010\text{J}$

Flashcard 97: Calculate the heat required to vaporize 100g of water, given $\text{ΔH}_{\text{vap}} = 2260 \text{J/g}$.

Answer: 226,000 J. $q = 100\text{g} \times 2260\text{J/g} = 226,000\text{J}$

Flashcard 98: What is the energy change associated with the phase change of deposition?

Answer: Latent heat of deposition. Energy released when gas transitions directly to solid.

Flashcard 99: What does the symbol $c$ represent in the formula $q = m \times c \times \text{ΔT}$?

Answer: Specific heat capacity. Energy required to raise temperature per unit mass per degree.

Flashcard 100: What is the energy change for converting 1 mole of solid directly to gas?

Answer: Molar heat of sublimation. Energy per mole for direct solid-to-gas transition.