Question

Metal halide which is insoluble in water is
A. $AgI$
B. $KBr$
C. $CaC{{l}_{2}}$
D. $AgF$

Answer 1

Hint: Solubility of metal halides depends on the size of the halide ion. More the size of the halide ion, the solubility of its corresponding salt. As we move from fluorine to iodine among halogens the size of the halogen atom increases.

Complete Step by Step Answer:
Solubility depends on the ionic character of the anion of metal halides. More the ionic character of the lithium halide, the more its lattice energy and it is more soluble in water.
Among the metal halides the silver metal is highly electropositive.
As we move from lithium fluoride to lithium iodide in lithium halides, the size of the halogen atom that is fluorine to iodine also increases. The polarisation power of the halides increases from fluorine to iodine so, ionic character decreases from lithium fluoride to lithium iodide and lattice energy also decreases. Thus silver iodide has the covalent character and that’s why it is highly insoluble in water.
Thus we can write that among the metal halides silver iodide is insoluble in water.
Thus the correct option is A.

Note: The metal halides are always ionic in nature. They dissociate into their corresponding ions when dissolved in water, which is a polar solvent. Thus the solution of metal halides conducts electricity.