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 physical property that affects heat transfer through conduction.

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

Flashcard 2: 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 3: 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 4: Define thermal conductivity.

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

Flashcard 5: Identify the process that transfers heat through electromagnetic waves.

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

Flashcard 6: Identify the type of heat transfer involved when touching a hot object.

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

Flashcard 7: 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 8: 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 9: What is the formula for heat capacity (C)?

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

Flashcard 10: Identify the formula for calculating the heat of vaporization.

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

Flashcard 11: Identify the process of heat transfer in fluids due to density differences.

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

Flashcard 12: 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 13: 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 14: 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 15: 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 16: 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 17: 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 18: What is the specific heat capacity of water?

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

Flashcard 19: 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 20: 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 21: 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 22: 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 23: State the unit of latent heat in the SI system.

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

Flashcard 24: State the equation for the first law of thermodynamics.

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

Flashcard 25: What is the formula for calculating heat transfer (q)?

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

Flashcard 26: 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 27: 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 28: 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 29: What is the main mechanism of heat transfer in gases?

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

Flashcard 30: What is the formula for calculating the heat of fusion?

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