Energy Diagrams and Thermal Equilibrium in Chemistry

This AP Chemistry lesson, led by Michael Farabaugh, covers Unit 6 on thermodynamics. It includes an introduction to key topics such as endothermic and exothermic processes, energy diagrams, heat transfer, and calorimetry. The lesson also discusses kinetics, reaction rates, and phase changes. Students are guided through solving problems using the ideal gas law and stoichiometry. The session concludes with AP practice problems and a homework assignment to reinforce learning.

What is the date of the AP Chemistry exam for this year?

• May 10th

• May 12th

• May 16th

• May 14th

In the warm-up problem, what is the ideal gas constant used?

• 0.08206 L·atm/mol·K

• 0.0806 L·atm/mol·K

• 0.08106 L·atm/mol·K

• 0.0821 L·atm/mol·K

What is the main reason for the increase in reaction rate at higher temperatures?

• Higher temperature decreases activation energy

• Higher temperature decreases the number of collisions

• Higher temperature increases the number of collisions

• Higher temperature increases the average kinetic energy of molecules

Tags

NGSS.HS-PS1-5

Which of the following is true for an endothermic process?

• The system releases heat

• Energy is transferred from the surroundings to the system

• The surroundings absorb heat

• Energy is transferred from the system to the surroundings

Tags

NGSS.HS-PS1-4

What is the change in temperature (ΔT) for the copper in the heat transfer experiment?

• 76.4°C

• 23.6°C

• 20°C

• 100°C

Tags

NGSS.HS-PS3-4

According to the first law of thermodynamics, what must be true if no heat is lost to the surroundings?

• The magnitude of heat lost by the copper is more than the heat gained by the water.

• The magnitude of heat lost by the copper is less than the heat gained by the water.

• The magnitude of heat lost by the copper is unrelated to the heat gained by the water.

• The magnitude of heat lost by the copper is equal to the heat gained by the water.

Tags

NGSS.HS-PS3-4

What is the specific heat capacity of water in joules per gram degrees Celsius?

• 5.18

• 6.18

• 4.18

• 3.18

Which sample will reach a higher final temperature if both have the same mass and absorb the same amount of heat?

• Water, because it has a lower specific heat capacity.

• Copper, because it has a higher specific heat capacity.

• Water, because it has a higher specific heat capacity.

• Copper, because it has a lower specific heat capacity.

What happens to the temperature of water when it reaches its melting point and more heat is added?

• The temperature decreases.

• The temperature remains constant until all the ice melts.

• The temperature continues to rise steadily.

• The temperature fluctuates.

Why does the enthalpy of vaporization for water require more energy than the enthalpy of fusion?

• Because water has a lower specific heat capacity in the liquid state.

• Because only some intermolecular forces are broken during vaporization.

• Because all intermolecular forces are broken during vaporization.

• Because water molecules are closer together in the liquid state.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4