Question

Place the following in order of decreasing magnitude of lattice energy.

KF MgS RbI
A) RbI>MgS>KF
B) KF>RbI>MgS
C) MgS>RbI>KF
D) MgS>KF>RbI
E) RbI>KF>MgS

Answer 1

The lattice energy of compounds is determined by the charges of the ions and the distance between them. In this case, RbI has the highest lattice energy, followed by MgS and KF.

Step-by-step explanation:

Lattice energy is a measure of the strength of the electrostatic attraction between ions in a crystal lattice. It depends on the charges of the ions and the distance between them. The greater the charges and the closer the ions, the higher the lattice energy.

In this case, we have KF, MgS, and RbI. The ionic charges are K⁺ and F⁻ for KF, Mg²⁺ and S²⁻ for MgS, and Rb⁺ and I⁻ for RbI. Now, if we compare the charges and the sizes of the ions, we can determine the order of decreasing lattice energy:

1. RbI
2. MgS
3. KF

Therefore, the correct answer is option A) RbI > MgS > KF.