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

Consider the following reaction: I2(g) + Cl2(g) ⇌ 2ICl(g) with Kp = 81.9 at 25 °C. Calculate ΔG⁰rxn for the reaction at 25 °C under standard conditions.

0 kJ/mol

11.4 kJ/mol

-81.9 kJ/mol

-11.4 kJ/mol

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Verified step by step guidance

Start by understanding the relationship between the equilibrium constant (Kp) and the standard Gibbs free energy change (ΔG⁰rxn) for a reaction. This relationship is given by the equation: ΔG⁰rxn = -RT ln(Kp), where R is the universal gas constant and T is the temperature in Kelvin.

Convert the temperature from Celsius to Kelvin. Since the temperature is given as 25 °C, add 273.15 to convert it to Kelvin: T = 25 + 273.15 = 298.15 K.

Identify the value of the universal gas constant (R) in appropriate units. For this calculation, use R = 8.314 J/(mol·K).

Substitute the values into the equation ΔG⁰rxn = -RT ln(Kp). Use the given Kp value of 81.9, the calculated temperature in Kelvin, and the gas constant: ΔG⁰rxn = - (8.314 J/(mol·K)) * (298.15 K) * ln(81.9).

Calculate the natural logarithm of Kp (ln(81.9) using a calculator or logarithm table), then multiply by the values of R and T, and finally apply the negative sign to find ΔG⁰rxn in Joules. Convert the result from Joules to kilojoules by dividing by 1000.