Q2(b). Dissociation of an ionic KF molecule
The ionic bond length for KF is 0.217 nm. Calculate the energy (in units of kJ/mol) required to dissociate a single molecule of KF into neutral atoms, K and F, using information provided below. Assume that potassium and fluorine ions are point charges. Potassium: ionization energy 418 kJ/mol, electron affinity 48 kJ/mol; fluorine: ionization energy 1680 kJ/mol, electron affinity 328 kJ/mol.
Answer in brief
The point-charge model gives approximately 5.50 × 10² kJ mol⁻¹ to form neutral K and F atoms.
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Coversionic bondCoulomb energyKF dissociation energyionization energyelectron affinity
All parts of Question 2
- 2(a) Particle in a one-dimensional box15 marks
- 2(b) Dissociation of an ionic KF molecule10 marks
- 2(c) Void fraction with one octahedral occupant15 marks