The solubility of metal halides depends on their nature, Lattice enthalpy and hydration enthalpy of the individual ions. Amongst fluorides of alkali metals, the lowest solubility of LiF in water is due to

Options

A. ionic nature of lithium fluoride
B. high lattice enthalpy
C. high hydration enthalpy for lithium ion
D. low ionisation enthalpy of lithium atom

Answer

B

Explanation

Solubilities of alkali metal halides in water can be explained in terms of lattice enthalpy and hydration ethalpies favour dissolution. Among fluorides, the order of solubility is `LiF lt NaF lt KF lt RbF lt CsF`. Low solubility of LiF is due to very high lattice energy. On moving down in the group LiF to CsF, solubility increases because lattice energy decreases. Except LiF, other halides of lithium are highly soluble in water.