The correct order of Delta_{f} H^{circ} value | vedclass

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(C) The standard enthalpy of formation $\Delta_{f} H^{\circ}$ for the most stable allotrope of an element is defined as $0 \ kJ/mol$.Graphite $(II)$ i

Vedclass · Accepted Answer

$III > I > II$

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(C) The standard enthalpy of formation $\Delta_{f} H^{\circ}$ for the most stable allotrope of an element is defined as $0 \ kJ/mol$.Graphite $(II)$ is the most stable allotrope of carbon, so its $\Delta_{f} H^{\circ} = 0 \ kJ/mol$.Diamond $(I)$ is less stable than graphite, with $\Delta_{f} H^{\circ} \approx 1.90 \ kJ/mol$.Fullerene $(III)$ is the least stable among these, with $\Delta_{f} H^{\circ} \approx 38.1 \ kJ/mol$.Therefore, the correct order of $\Delta_{f} H^{\circ}$ values is $III > I > II$.

The correct order of $\Delta_{f} H^{\circ}$ values of Diamond $(I)$, Graphite $(II)$, and Fullerene $(III)$ is:

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