Question

The ionization energy of $F^{-}$ is 320 kJ/mole. The electron gain enthalpy of fluorine is:

• A. -320 KJ/mole
• B. -160 KJ/mole
• C. 320 KJ/mole
• D. 160 KJ/mole

Answer 1

The correct option is A

-320 KJ/mole

Ionization energy is the energy needed to take an electron from an atom. Halogens have the most negative electron gain enthalpy. Ionization energy is exactly opposite to electron gain enthalpy in this case.
$F^{-}⟶$ F + $e^{-}$
$\Delta H=320kJ/mole(I.E)$

$F+e^{-}⟶$ $F^{-}$
$\Delta H=-320kJ/mole(I.E)$