For water, at and at . Assuming the enthalpies are temperature-independent, what is…

CHEMISTRY · Single correct · AP · Chemistry · Thermochemistry · Thermochemistry

Problem

For water,

\Delta H_{\mathrm{fus}} = 6.01\,\text{kJ\,mol}^{-1}

0\,^\circ\text{C}

and

\Delta H_{\mathrm{vap}} = 40.7\,\text{kJ\,mol}^{-1}

100\,^\circ\text{C}

. Assuming the enthalpies are temperature-independent, what is the molar enthalpy change for sublimation of ice at

0\,^\circ\text{C}

, and how would this appear on an energy diagram? (a)

40.7\,\text{kJ\,mol}^{-1}

absorbed; single upward arrow from solid to gas. (b)

46.7\,\text{kJ\,mol}^{-1}

released; single downward arrow from gas to solid. (c)

46.7\,\text{kJ\,mol}^{-1}

absorbed; single upward arrow from solid to gas. (d)

34.7\,\text{kJ\,mol}^{-1}

absorbed; single upward arrow from solid to gas.