AP CHEMISTRY 2022 EXAM Section 1: Multiple Choice

A quantity of 10,000 J of thermal energy is transferred to four different substances. In which of the following experiments could the greatest mass of the given substance undergo the indicated change?

• Melting ice at 0°C to form liquid water at 0°C (ΔHfus = 330 J/g)

• Boiling liquid acetone at 56°C to form acetone vapor at 56°C (ΔHvap = 540 J/g)

• Increasing the temperature of liquid glycerin from 20°C to 120°C (Specific heat = 2.4 J/(g·°C))

• Increasing the temperature of solid copper from 0°C to 200°C (Specific heat = 0.40 J/(g·°C))

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4

Which of the following questions about the components in a mixture could be investigated with a paper chromatography experiment?

• Do the components have different densities?

• Do the components have different molecular masses?

• Do the components have different molecular polarities?

• Do the components have different average molecular speeds?

Based on the bond enthalpies given in the table above, which of the following is the best estimate of ΔH° for the reaction represented below? CH₄ + F₂ → CH₃F + HF

• −650 kJ/molrxn

• −490 kJ/molrxn

• +490 kJ/molrxn

• +650 kJ/molrxn

Tags

NGSS.HS-PS1-4

Based on the Ka values listed in the table above, equal volumes of which of the following pairs of solutions when mixed together will result in a buffer solution with a pH between 7 and 8?

• 0.10 M HC2H3O2(aq) and 0.10 M HF(aq)

• 0.10 M HC2H3O2(aq) and 0.10 M NaC2H3O2(aq)

• 0.10 M HC2H3O2(aq) and 0.10 M HCN(aq)

• 0.10 M HClO(aq) and 0.10 M NaClO(aq)

A proposed mechanism for the destruction of O3(g) in the upper atmosphere is represented above. Which of the following is the catalyst in the proposed mechanism?

• O(g)

• Cl(g)

• ClO(g)

• O2(g)

A 10.0 mL sample of 1.0 M AgNO3(aq) and a 10.0 mL sample of 1.0 M NaBr(aq), both originally at 25°C, are combined in a constant-pressure calorimeter where the reaction represented above occurs. If the final temperature of the mixture is 35°C, what is the value of ΔH for the reaction? (Assume that the heat absorbed by the calorimeter is negligible, that the total mass of the mixture is 20.0 g, and that the specific heat capacity of the mixture is 4.2 J/(g·°C).)

• −84,000 J/molrxn

• −84 J/molrxn

• +84 J/molrxn

• +84,000 J/molrxn

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

NGSS.HS-PS3-4

A sample of ice at 0°C is added to 100. g of water at 33°C. The mixture is stirred gently until the temperature of the water is 0°C. All of the remaining ice is quickly removed. Based on the information in the table above, the mass of ice that melted is closest to

• 0.13 g

• 0.42 g

• 1.3 g

• 42 g

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4

A vessel initially contains H2O(g) at a partial pressure of 0.30 atm, CO(g) at a partial pressure of 0.10 atm, CO2(g) at a partial pressure of 1.5 atm, and H2(g) at a partial pressure 10. atm at 500 K. Which of the following occurs as the system approaches equilibrium at 500 K?

• The partial pressures of H2O(g) and CO(g) increase because Q > Kp.

• The partial pressures of H2O(g) and CO(g) increase because Q < Kp.

• The partial pressures of CO2(g) and H2(g) increase because Q > Kp.

• The partial pressures of CO2(g) and H2(g) increase because Q < Kp.

Tags

NGSS.HS-PS1-5

Which of the following changes will increase the amount of NO2(g) in the equilibrium system represented by the equation above?

• Removing CO(g) from the system

• Removing CO2(g) from the system

• Increasing the volume of the reaction vessel

• Decreasing the volume of the reaction vessel

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-6

Which of the following pairs of diagrams represents the change with the greatest positive value of ΔS°?

• Diagram A

• Diagram B

• Diagram C

• Diagram D

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4