Answer:
CaO > SrO > NaF > KCl
Explanation:
The lattice dissociation energy (LE) is the energy needed to convert 1 mol of the solid crystal into gaseous ions.
A simplified formula for lattice energy is
[tex]LE = \dfrac{\kappa q_{1}q_{2}}{r}[/tex]
where q₁ and q₂ are the ionic charges, r is the interionic distance, and κ is a constant.
Thus, lattice energies increase as the
The compounds written in their ionic forms are
Ca²⁺O²⁻, Na⁺F⁻, Sr²⁺O²⁻, and K⁺Cl⁻
We can separate them into two groups:
(1,1) = NaF and KCl
(2,2) = CaO and SrO
The (1,1) compounds have smaller lattice energies than their (2,2) counterparts.
K⁺ and Cl⁻ are larger ions than Na⁺ and F⁻, so the lattice energy of KCl is less than that of NaF.
Sr²⁺ is a larger cation than Ca²⁺, so the lattice energy of SrO is less than that of CaO.
The order of lattice energies is
CaO > SrO > NaF > KCl
