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the value of δ g° at 25 °c for the decomposition of pocl3 into its constituent elements, 2pocl3 (g) → p2 (g) o2 (g) 3cl2 (g) is ________ kj/mol.

2 Answers

7 votes

Final answer:

The precise value of ΔG° for the decomposition of POCl3 cannot be calculated without standard free energies of formation. These values are not provided here but can be found in standard chemical references or databases.

Step-by-step explanation:

The student's question pertains to the standard free energy change (ΔG°) for the decomposition of phosphorus oxychloride (POCl3) into its constituent elements. To answer this question, one would typically look up the standard free energies of formation (ΔG°) of all the products and reactants involved, and apply the formula:

ΔG° = ∑ΔG°(products) - ∑ΔG°(reactants)

Without having the standard free energies of formation values provided in the question or accessible reference materials, calculating the precise value of ΔG° for this reaction is not possible. Normally, these values are found in standard chemical reference material or databases. The procedure involves using the standard free energy of formation for phosphorus (P2), oxygen (O2), and chlorine (Cl2) gases and subtracting the value for phosphorus oxychloride. Since we cannot provide the exact value, I recommend consulting a chemical reference to find the necessary ΔG° values to perform this calculation.

User Whymath
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4 votes

Final answer:

Calculating the standard Gibbs free energy change for the decomposition of POCl3 requires thermodynamic properties that aren't provided in the question, and typically involves using the equation ΔG° = ΔH° - TΔS° at 298 K.

Step-by-step explanation:

The question relates to calculating the standard Gibbs free energy change (ΔG°) for the decomposition of POCl3 into its constituent elements. Without the given values for ΔH° (enthalpy change), ΔS° (entropy change), or the direct value for ΔG°, the student is expected to refer to standard thermodynamic tables or computational methods to find or estimate these values for the reaction: 2POCl3 (g) → P2 (g) + O2 (g) + 3Cl2 (g).

To calculate the ΔG° for the reaction at 25 °C (or 298 K), one would typically use the equation ΔG° = ΔH° - TΔS°, where T is the temperature in Kelvin. The thermodynamic properties of POCl3, P2, O2, and Cl2 would be necessary to determine ΔH° and ΔS°.

User Patrik Laszlo
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7.9k points