Question

6 mark for review compound lattice energy (kj/mol) naf 930 mgf₂ 2978 the energy required to dissociate an ionic solid into gaseous ions (lattice energy) for the compounds naf and mgf₂ is shown in the table above. on the basis of coulombs law, which of the following best helps to explain the large difference between the lattice energies of naf and mgf₂? a the solubility of mgf₂ is less than that of naf. b the electronegativity of mg is greater than that of na. c the mass of the mg cation is greater than that of the na cation. d the charge of the mg cation is larger than that of the na cation.

Explanation:

Coulomb's law states that the force of attraction between two charged particles is directly proportional to the product of their charges and inversely proportional to the square of the distance between them. In ionic compounds, lattice energy is related to the strength of the ionic bonds. The $Na^+$ ion has a charge of +1 and the $Mg^{2 +}$ ion has a charge of +2. A higher - charged cation results in a stronger electrostatic attraction to the anion ($F^-$ in this case), leading to a higher lattice energy. Solubility, electronegativity, and mass are not directly related to lattice energy as described by Coulomb's law in this context.

Answer:

D. The charge of the Mg cation is larger than that of the Na cation.