Table of contents

1. Intro to General Chemistry3h 48m
2. Atoms & Elements4h 16m
3. Chemical Reactions4h 10m
4. BONUS: Lab Techniques and Procedures1h 38m
5. BONUS: Mathematical Operations and Functions48m
6. Chemical Quantities & Aqueous Reactions3h 53m
7. Gases3h 49m
8. Thermochemistry2h 37m
9. Quantum Mechanics2h 58m
10. Periodic Properties of the Elements3h 9m
11. Bonding & Molecular Structure3h 29m
12. Molecular Shapes & Valence Bond Theory1h 57m
13. Liquids, Solids & Intermolecular Forces2h 23m
14. Solutions3h 1m
15. Chemical Kinetics2h 53m
16. Chemical Equilibrium2h 29m
17. Acid and Base Equilibrium5h 1m
18. Aqueous Equilibrium4h 47m
19. Chemical Thermodynamics1h 50m
20. Electrochemistry2h 42m
21. Nuclear Chemistry2h 36m
22. Organic Chemistry5h 7m
23. Chemistry of the Nonmetals2h 39m
24. Transition Metals and Coordination Compounds3h 16m

19. Chemical Thermodynamics

Gibbs Free Energy Calculations

General Chemistry

19. Chemical Thermodynamics

Gibbs Free Energy Calculations

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Multiple Choice

What is ΔG (in kJ) for the formation of solid UF6 from uranium and fluorine at 25 °C when the partial pressure of F2 is 0.045 atm, given that the standard free energy of formation of UF6(s) is -2068 kJ/mol? Is the reaction spontaneous in the forward or the reverse direction?

-2068 kJ, spontaneous in the forward direction

-2075 kJ, spontaneous in the reverse direction

-2060 kJ, spontaneous in the reverse direction

-2075 kJ, spontaneous in the forward direction

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Verified step by step guidance

Identify the reaction: The formation of solid UF6 from uranium and fluorine can be represented as: U(s) + 3F2(g) → UF6(s).

Understand the concept: The Gibbs free energy change (ΔG) for a reaction can be calculated using the equation ΔG = ΔG° + RTlnQ, where ΔG° is the standard Gibbs free energy change, R is the universal gas constant (8.314 J/mol·K), T is the temperature in Kelvin, and Q is the reaction quotient.

Convert temperature: Convert the given temperature from Celsius to Kelvin by adding 273.15. So, T = 25 + 273.15 = 298.15 K.

Calculate the reaction quotient (Q): For the reaction U(s) + 3F2(g) → UF6(s), the reaction quotient Q is given by the expression Q = [UF6]/[F2]^3. Since UF6 is a solid, its activity is 1, and Q = 1/(0.045)^3.

Substitute values into the ΔG equation: Use the equation ΔG = ΔG° + RTlnQ, where ΔG° = -2068 kJ/mol, R = 8.314 J/mol·K (convert to kJ by dividing by 1000), T = 298.15 K, and Q is calculated from the previous step. Calculate ΔG to determine the spontaneity of the reaction.