Question

Which of the following statements is true for the given reaction?

\[\ce{Na(s) -> Na(g); \triangle H^Θ = 108.4 kJ}\] mol⁻¹

Options

• The enthalpy of atomization is same as the enthalpy of vaporisation.

• The enthalpy of atomization is same as the enthalpy of sublimation.

• The enthalpy of atomization is same as the bond enthalpy.

• The enthalpy of atomization is same as the enthalpy of solution.

Answer 1

The enthalpy of atomization is same as the enthalpy of sublimation.

Explanation:

Enthalpy of atomization is the heat required to produce gaseous atoms from the element in its standard state. For a metal like Na, converting \[\ce{Na(s) -> Na(g)}\] is sublimation (solid → gas) and yields gaseous atoms, so ΔHat = ΔHsub.

(Enthalpy of vaporization refers to liquid → gas; bond enthalpy applies to breaking molecular bonds, and solution enthalpy is a different process.)