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: 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 2: Identify the process that transfers heat through electromagnetic waves.

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

Flashcard 3: Identify the process of heat transfer in fluids due to density differences.

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

Flashcard 4: 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 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: 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 7: What is the formula for heat capacity (C)?

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

Flashcard 8: State the equation for the first law of thermodynamics.

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

Flashcard 9: Identify the process that transfers heat through electromagnetic waves.

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

Flashcard 10: 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 11: 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 12: 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 13: State the unit of latent heat in the SI system.

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

Flashcard 14: 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 15: What is the formula for calculating the heat of fusion?

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

Flashcard 16: 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 17: 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 18: Identify the process of heat transfer in fluids due to density differences.

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

Flashcard 19: 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 20: 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 21: 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 22: 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 23: 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 24: 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 25: 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 26: What is the formula for calculating the heat of fusion?

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

Flashcard 27: 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 28: 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 29: What is the formula for heat capacity (C)?

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

Flashcard 30: 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 31: 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 32: 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 33: 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 34: 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 35: 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 36: 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 37: What is the formula for calculating the heat of fusion?

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

Flashcard 38: Identify the formula for calculating the heat of vaporization.

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

Flashcard 39: Identify the type of heat transfer involved when touching a hot object.

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

Flashcard 40: 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 41: 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 42: 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 43: State the equation for the first law of thermodynamics.

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

Flashcard 44: Identify the physical property that affects heat transfer through conduction.

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

Flashcard 45: Identify the physical property that affects heat transfer through conduction.

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

Flashcard 46: 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 47: What is the specific heat capacity of water?

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

Flashcard 48: 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 49: State the equation for the first law of thermodynamics.

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

Flashcard 50: What is the formula for heat capacity (C)?

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

Flashcard 51: 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 52: 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 53: 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 54: Define thermal conductivity.

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

Flashcard 55: 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 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 specific heat capacity of water?

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

Flashcard 58: 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 59: State the equation for the first law of thermodynamics.

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

Flashcard 60: 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 61: 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 62: 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 63: What is the formula for calculating heat transfer (q)?

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

Flashcard 64: 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 65: 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 66: What is the formula for calculating the heat of fusion?

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

Flashcard 67: 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 68: 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 69: 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 70: 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 71: 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 72: 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 73: 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 74: What is the main mechanism of heat transfer in gases?

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

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

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

Flashcard 78: Identify the process that transfers heat through electromagnetic waves.

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

Flashcard 79: 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 80: 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 81: 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 82: 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 83: Identify the formula for calculating the heat of vaporization.

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

Flashcard 84: Define thermal conductivity.

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

Flashcard 85: What is the main mechanism of heat transfer in gases?

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

Flashcard 86: Identify the process of heat transfer in fluids due to density differences.

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

Flashcard 87: State the unit of latent heat in the SI system.

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

Flashcard 88: Identify the process of heat transfer in fluids due to density differences.

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

Flashcard 89: Identify the formula for calculating the heat of vaporization.

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

Flashcard 90: 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 91: What is the specific heat capacity of water?

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

Flashcard 92: 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 93: Identify the type of heat transfer involved when touching a hot object.

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

Flashcard 94: 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 95: 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 96: 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 97: What is the formula for heat capacity (C)?

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

Flashcard 98: 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 99: 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 100: 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.