What effect does low lattice enthalpy have on solids?

Low lattice enthalpy in solids is primarily associated with weaker ionic interactions, which can result from a combination of smaller charges on the ions and greater distances between them. Lattice enthalpy is the energy required to separate one mole of a solid ionic compound into gaseous ions; thus, low lattice enthalpy indicates that the attraction between the ions in the lattice is weaker. This situation typically arises when ions have a smaller charge, since charge directly influences the strength of ionic interactions. Additionally, larger ionic radii (which often lead to greater distances between ions) can also contribute to low lattice enthalpy, as they result in a weaker electrostatic attraction.

Solid stability, density, and melting point are all influenced by lattice enthalpy but are not directly increased with low lattice enthalpy. In fact, solids with low lattice enthalpies tend to be less stable, have lower densities, and generally lower melting points because weaker ionic bonds mean less energy is required to break the solid structure. Therefore, the effects associated with low lattice enthalpy are clearly related to the charge and distance between the constituent ions, making this reasoning valid.