AP Chemistry Flashcards: Heat Transfer And Thermal Equilibrium

What this deck covers

This deck focuses on Heat Transfer And Thermal Equilibrium, 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: Identify the process that transfers heat through electromagnetic waves.

Answer: Radiation. Energy travels as photons without requiring matter.

Flashcard 2: Identify the process of heat transfer in fluids due to density differences.

Answer: Convection. Bulk fluid motion transfers heat via density differences.

Flashcard 3: Define specific heat capacity.

Answer: The amount of heat required to raise the temperature of 1 g of a substance by 1°C. Measures the thermal energy needed per gram per degree Celsius.

Flashcard 4: Calculate the energy required to melt 100 g of ice. $L_f = 333 \text{ J/g}$

Answer: $q = 100 \times 333 = 33300 \text{ J}$. Apply $q = mL_f$ for melting calculations.

Flashcard 5: Calculate the energy required to melt 100 g of ice. $L_f = 333 \text{ J/g}$

Answer: $q = 100 \times 333 = 33300 \text{ J}$. Apply $q = mL_f$ for melting calculations.

Flashcard 6: Identify the process that transfers heat through electromagnetic waves.

Answer: Radiation. Energy travels as photons without requiring matter.

Flashcard 7: What is the relationship between heat transfer and temperature change?

Answer: Heat transfer results in a temperature change in the substance. Heat flow changes molecular kinetic energy and temperature.

Flashcard 8: State the Law of Conservation of Energy in the context of heat transfer.

Answer: Energy cannot be created or destroyed, only transferred or converted. Energy remains constant in isolated systems during heat transfer.

Flashcard 9: What happens to the temperature of a substance as it undergoes a phase change?

Answer: The temperature remains constant during a phase change. Energy goes to breaking bonds, not increasing kinetic energy.

Flashcard 10: Calculate the final temperature when 200 g of water at 60°C is mixed with 200 g of water at 20°C.

Answer: Final temperature is 40°C. Equal masses mix to the average of initial temperatures.

Flashcard 11: What is the formula for calculating the heat of fusion?

Answer: $q = mL_f$. Heat equals mass times latent heat of fusion.

Flashcard 12: What is the heat of vaporization?

Answer: The heat required to convert a liquid to gas at its boiling point. Energy needed to convert liquids to gas phase.

Flashcard 13: What is thermal equilibrium?

Answer: It is the state when two objects reach the same temperature and no heat flows. Equal temperatures mean zero net heat flow between objects.

Flashcard 14: Identify the process of heat transfer in fluids due to density differences.

Answer: Convection. Bulk fluid motion transfers heat via density differences.

Flashcard 15: Calculate the final temperature when 200 g of water at 60°C is mixed with 200 g of water at 20°C.

Answer: Final temperature is 40°C. Equal masses mix to the average of initial temperatures.

Flashcard 16: How is heat capacity different from specific heat capacity?

Answer: Heat capacity is the heat required to raise the temperature of an object by 1°C. Heat capacity depends on total mass, not per unit mass.

Flashcard 17: Which formula is used to calculate the change in temperature?

Answer: $\triangle T = T_{final} - T_{initial}$. Change equals final minus initial temperature values.

Flashcard 18: How is heat capacity different from specific heat capacity?

Answer: Heat capacity is the heat required to raise the temperature of an object by 1°C. Heat capacity depends on total mass, not per unit mass.

Flashcard 19: Identify the unit for specific heat capacity in the SI system.

Answer: J/g°C. Standard units for energy per mass per temperature change.

Flashcard 20: What is the significance of a substance's specific heat capacity?

Answer: It indicates how much heat is needed to change the temperature. Higher values mean more energy needed for temperature change.

Flashcard 21: What is the formula for heat transfer in a calorimeter?

Answer: $q_{system} = -q_{surroundings}$. Heat lost by one equals heat gained by another.

Flashcard 22: Define latent heat.

Answer: The heat required to change the phase of a unit mass of a substance without temperature change. Energy needed for phase transitions at constant temperature.

Flashcard 23: What is the formula for heat capacity (C)?

Answer: $C = mc$. Total heat capacity equals mass times specific heat capacity.

Flashcard 24: Identify the direction of heat flow between two objects.

Answer: Heat flows from the hotter object to the cooler object. Heat naturally flows from high to low temperature regions.

Flashcard 25: What is the significance of a substance's specific heat capacity?

Answer: It indicates how much heat is needed to change the temperature. Higher values mean more energy needed for temperature change.

Flashcard 26: Identify the formula to find the change in internal energy of a system.

Answer: $\triangle U = q + w$. First law of thermodynamics relates energy, heat, and work.

Flashcard 27: What is the latent heat of fusion?

Answer: The heat required to convert a solid to a liquid at its melting point. Energy to melt solids at their melting point.

Flashcard 28: What is the formula for calculating the heat of fusion?

Answer: $q = mL_f$. Heat equals mass times latent heat of fusion.

Flashcard 29: Identify the formula for calculating the heat of vaporization.

Answer: $q = mL_v$. Heat equals mass times latent heat of vaporization.

Flashcard 30: Identify the type of heat transfer involved when touching a hot object.

Answer: Conduction. Direct contact transfers kinetic energy between molecules.

Flashcard 31: What is thermal equilibrium?

Answer: It is the state when two objects reach the same temperature and no heat flows. Equal temperatures mean zero net heat flow between objects.

Flashcard 32: Calculate the heat required to vaporize 200 g of water. $L_v = 2260 \text{ J/g}$

Answer: $q = 200 \times 2260 = 452000 \text{ J}$. Apply $q = mL_v$ for vaporization energy calculations.

Flashcard 33: Calculate the heat absorbed when 50 g of water is heated from 20°C to 70°C. $c_{water} = 4.18 \text{ J/g°C}$

Answer: $q = 50 \times 4.18 \times (70 - 20) = 10450 \text{ J}$. Apply $q = mc\triangle T$ with given values.

Flashcard 34: State the equation for the first law of thermodynamics.

Answer: $\triangle U = q + w$. Internal energy change equals heat plus work done.

Flashcard 35: Identify the physical property that affects heat transfer through conduction.

Answer: Thermal conductivity. High conductivity allows easier heat flow through materials.

Flashcard 36: Calculate the heat required to vaporize 200 g of water. $L_v = 2260 \text{ J/g}$

Answer: $q = 200 \times 2260 = 452000 \text{ J}$. Apply $q = mL_v$ for vaporization energy calculations.

Flashcard 37: What is the specific heat capacity of water?

Answer: 4.18 J/g°C. Standard reference value for aqueous solution calculations.

Flashcard 38: What is the role of a calorimeter?

Answer: To measure the heat of chemical reactions or physical changes. Device isolates systems to measure thermal energy changes.

Flashcard 39: State the equation for the first law of thermodynamics.

Answer: $\triangle U = q + w$. Internal energy change equals heat plus work done.

Flashcard 40: What is the formula for heat capacity (C)?

Answer: $C = mc$. Total heat capacity equals mass times specific heat capacity.

Flashcard 41: Identify the unit for specific heat capacity in the SI system.

Answer: J/g°C. Standard units for energy per mass per temperature change.

Flashcard 42: Define thermal conductivity.

Answer: A material's ability to conduct heat. Quantifies how well materials conduct thermal energy.

Flashcard 43: What happens to the temperature of a substance as it undergoes a phase change?

Answer: The temperature remains constant during a phase change. Energy goes to breaking bonds, not increasing kinetic energy.

Flashcard 44: What is the specific heat capacity of water?

Answer: 4.18 J/g°C. Standard reference value for aqueous solution calculations.

Flashcard 45: State the equation for the first law of thermodynamics.

Answer: $\triangle U = q + w$. Internal energy change equals heat plus work done.

Flashcard 46: Find the specific heat capacity if 500 J raises 10 g of a substance by 5°C.

Answer: $c = \frac{500}{10 \times 5} = 10 \text{ J/g°C}$. Rearrange $q = mc\triangle T$ to solve for $c$.

Flashcard 47: What is the principle of calorimetry?

Answer: The heat lost by hot objects equals the heat gained by cold ones. Energy conservation in thermal systems during heat exchange.

Flashcard 48: Identify the direction of heat flow between two objects.

Answer: Heat flows from the hotter object to the cooler object. Heat naturally flows from high to low temperature regions.

Flashcard 49: State the condition for two systems to be in thermal equilibrium.

Answer: They must have the same temperature. No temperature difference means no driving force for heat flow.

Flashcard 50: What is the formula for calculating the heat of fusion?

Answer: $q = mL_f$. Heat equals mass times latent heat of fusion.

Flashcard 51: Define specific heat capacity.

Answer: The amount of heat required to raise the temperature of 1 g of a substance by 1°C. Measures the thermal energy needed per gram per degree Celsius.

Flashcard 52: Identify the unit for specific heat capacity in the SI system.

Answer: J/g°C. Standard units for energy per mass per temperature change.

Flashcard 53: What is the role of a calorimeter?

Answer: To measure the heat of chemical reactions or physical changes. Device isolates systems to measure thermal energy changes.

Flashcard 54: What is the role of a calorimeter?

Answer: To measure the heat of chemical reactions or physical changes. Device isolates systems to measure thermal energy changes.

Flashcard 55: Calculate the temperature change if 1000 J of heat is added to 50 g of a substance with $c = 2 \text{ J/g°C}$.

Answer: $\triangle T = \frac{1000}{50 \times 2} = 10°C$. Rearrange heat equation to solve for temperature change.

Flashcard 56: What happens to the temperature of a substance as it undergoes a phase change?

Answer: The temperature remains constant during a phase change. Energy goes to breaking bonds, not increasing kinetic energy.

Flashcard 57: What is the main mechanism of heat transfer in gases?

Answer: Convection. Gas molecules move freely, enabling bulk heat transfer.

Flashcard 58: Define latent heat.

Answer: The heat required to change the phase of a unit mass of a substance without temperature change. Energy needed for phase transitions at constant temperature.

Flashcard 59: Identify the type of heat transfer involved when touching a hot object.

Answer: Conduction. Direct contact transfers kinetic energy between molecules.

Flashcard 60: Define latent heat.

Answer: The heat required to change the phase of a unit mass of a substance without temperature change. Energy needed for phase transitions at constant temperature.

Flashcard 61: What is the formula for heat transfer in a calorimeter?

Answer: $q_{system} = -q_{surroundings}$. Heat lost by one equals heat gained by another.

Flashcard 62: Identify the direction of heat flow between two objects.

Answer: Heat flows from the hotter object to the cooler object. Heat naturally flows from high to low temperature regions.

Flashcard 63: Identify the formula for calculating the heat of vaporization.

Answer: $q = mL_v$. Heat equals mass times latent heat of vaporization.

Flashcard 64: What is the main mechanism of heat transfer in gases?

Answer: Convection. Gas molecules move freely, enabling bulk heat transfer.

Flashcard 65: Identify the process of heat transfer in fluids due to density differences.

Answer: Convection. Bulk fluid motion transfers heat via density differences.

Flashcard 66: State the unit of latent heat in the SI system.

Answer: J/kg. Energy per kilogram for phase change processes.

Flashcard 67: Identify the formula for calculating the heat of vaporization.

Answer: $q = mL_v$. Heat equals mass times latent heat of vaporization.

Flashcard 68: What is the specific heat capacity of water?

Answer: 4.18 J/g°C. Standard reference value for aqueous solution calculations.

Flashcard 69: Calculate the energy required to melt 100 g of ice. $L_f = 333 \text{ J/g}$

Answer: $q = 100 \times 333 = 33300 \text{ J}$. Apply $q = mL_f$ for melting calculations.

Flashcard 70: Identify the type of heat transfer involved when touching a hot object.

Answer: Conduction. Direct contact transfers kinetic energy between molecules.

Flashcard 71: Calculate the final temperature when 200 g of water at 60°C is mixed with 200 g of water at 20°C.

Answer: Final temperature is 40°C. Equal masses mix to the average of initial temperatures.

Flashcard 72: State the condition for two systems to be in thermal equilibrium.

Answer: They must have the same temperature. No temperature difference means no driving force for heat flow.

Flashcard 73: Find the specific heat capacity if 500 J raises 10 g of a substance by 5°C.

Answer: $c = \frac{500}{10 \times 5} = 10 \text{ J/g°C}$. Rearrange $q = mc\triangle T$ to solve for $c$.

Flashcard 74: What is the formula for heat capacity (C)?

Answer: $C = mc$. Total heat capacity equals mass times specific heat capacity.

Flashcard 75: State the condition for two systems to be in thermal equilibrium.

Answer: They must have the same temperature. No temperature difference means no driving force for heat flow.

Flashcard 76: What is the formula for heat transfer in a calorimeter?

Answer: $q_{system} = -q_{surroundings}$. Heat lost by one equals heat gained by another.

Flashcard 77: What is the formula for calculating heat transfer (q)?

Answer: $q = mc\triangle T$. Heat equals mass times specific heat times temperature change.

Flashcard 78: State the unit of latent heat in the SI system.

Answer: J/kg. Energy per kilogram for phase change processes.

Flashcard 79: Define specific heat capacity.

Answer: The amount of heat required to raise the temperature of 1 g of a substance by 1°C. Measures the thermal energy needed per gram per degree Celsius.

Flashcard 80: What is the main mechanism of heat transfer in gases?

Answer: Convection. Gas molecules move freely, enabling bulk heat transfer.

Flashcard 81: State the unit of latent heat in the SI system.

Answer: J/kg. Energy per kilogram for phase change processes.

Flashcard 82: What is thermal equilibrium?

Answer: It is the state when two objects reach the same temperature and no heat flows. Equal temperatures mean zero net heat flow between objects.

Flashcard 83: Identify the process that transfers heat through electromagnetic waves.

Answer: Radiation. Energy travels as photons without requiring matter.

Flashcard 84: Which heat transfer method does not require a medium?

Answer: Radiation. Transfers energy through electromagnetic waves, no medium needed.

Flashcard 85: What is the principle of calorimetry?

Answer: The heat lost by hot objects equals the heat gained by cold ones. Energy conservation in thermal systems during heat exchange.

Flashcard 86: What is the heat of vaporization?

Answer: The heat required to convert a liquid to gas at its boiling point. Energy needed to convert liquids to gas phase.

Flashcard 87: What is the principle of calorimetry?

Answer: The heat lost by hot objects equals the heat gained by cold ones. Energy conservation in thermal systems during heat exchange.

Flashcard 88: What is the significance of a substance's specific heat capacity?

Answer: It indicates how much heat is needed to change the temperature. Higher values mean more energy needed for temperature change.

Flashcard 89: Find the specific heat capacity if 500 J raises 10 g of a substance by 5°C.

Answer: $c = \frac{500}{10 \times 5} = 10 \text{ J/g°C}$. Rearrange $q = mc\triangle T$ to solve for $c$.

Flashcard 90: How is heat capacity different from specific heat capacity?

Answer: Heat capacity is the heat required to raise the temperature of an object by 1°C. Heat capacity depends on total mass, not per unit mass.

Flashcard 91: What is the heat of vaporization?

Answer: The heat required to convert a liquid to gas at its boiling point. Energy needed to convert liquids to gas phase.