Explain the following:
(a) Lithium iodide is more covalent than lithium fluoride
(b) Lattice enthalpy of LiF is maximum among all the alkali metal halides.

Explanation

Lithium iodide is more covalent than Lithium chloride as the size of `I^(-)` is larger than `CI^(-)` 1on. Hence `I^(-)` 1on will be more polarised than `CI^(-)` ion by the cation `Li^(+)`. So LiI is more covalent than LiC1.