Define lattice enthalpy and arrange the following in increasing order of lattice enthalpy.
            (a)        LiCl, CsCl, NaCl, KCl, RbCl
            (b)        AlF₃, NaF, MgF₂
            (c)        NaCl, MgO, MgCl₂ and LiCl

Question

Define lattice enthalpy and arrange the following in increasing
order of lattice enthalpy
(a) LiCl, CsCl, NaCl, KCl, RbCl
(b) AlF3, NaF, MgF2
(c) NaCl, MgO, MgCl2 and LiCl

Vartika Jain · Accepted Answer

Dear Student,

Lattice enthalpy is defined as the energy required to completely separate one mole of solid ionic compound into gaseous constituent ions
It is a measure of stability of ionic compounds
 (a) As we move down the group, size of the element increases
 Here the anion is constant
 Lattice enthalpy is inversely related to size of cation
 Therefore, order will be CsCl < RbCl < KCl < NaCl < LiCl(b) Smaller size and higher charge of cation favours higher lattice enthalpy
 Hence, order will be NaF < MgF2 < AlF3(c) Higher charge on ions, higher is the lattice enthalpy
 Hence, the order will beNaCl < MgCl2 < LiCl < MgO

Define lattice enthalpy and arrange the following in increasing order of lattice enthalpy. (a) LiCl, CsCl, NaCl, KCl, RbCl (b) AlF3, NaF, MgF2 (c) NaCl, MgO, MgCl2 and LiCl

Define lattice enthalpy and arrange the following in increasing order of lattice enthalpy.
(a) LiCl, CsCl, NaCl, KCl, RbCl
(b) AlF₃, NaF, MgF₂
(c) NaCl, MgO, MgCl₂ and LiCl