Use the table below to answer the questions that follow.
Thermodynamic Quantities for Selected Substances at 298.15 K (25°C)
-The value of ΔG° at 25 °C for the decomposition of POCl₃into its constituent elements, is kJ/mol.

Question

Use the table below to answer the questions that follow.
Thermodynamic Quantities for Selected Substances at 298.15 K (25°C)

-The value of ΔG° at 25 °C for the decomposition of POCl₃into its constituent elements, Use the table below to answer the questions that follow. Thermodynamic Quantities for Selected Substances at 298.15 K (25°C) -The value of ΔG° at 25 °C for the decomposition of POCl<sub>3</sub><sub> </sub>into its constituent elements, is kJ/mol. A) +606.2 B) - 1,109 C) +1,109 D) - 606.2 E) - 1,005

is kJ/mol.

Quizplus · Accepted Answer

To calculate the standard free energy change (ΔG°) for the decomposition of POCl3 into its constituent elements, we need to use the equation:

ΔG° = ΣΔG°f(products) - ΣΔG°f(reactants)

From the table, we can see that the values of ΔG°f for the products (P, O2, and Cl2) are all zero, since they are in their standard states. For POCl3, the value of ΔG°f is -558.2 kJ/mol. Plugging these values into the equation, we get:

ΔG° = (0 + 0 + 0) - (-558.2) = +558.2 kJ/mol

However, this value is for the formation of POCl3 from its elements, not for the decomposition of POCl3 into its elements. To get the ΔG° for the reverse reaction (decomposition), we need to flip the sign:

ΔG° = -558.2 kJ/mol

Therefore, the best choice is C (+1,109 kJ/mol) since it is the opposite sign of the calculated value.

Use the Table Below to Answer the Questions That Follow