Most readily hydrolyzed halide is:

The ease with which a halide ion (X-) can undergo hydrolysis depends on the stability of the resulting products and the strength of the X-H bond in the hydrohalic acid (HX) formed. In general, the order of hydrolysis reactivity for halide ions is as follows:

Iodide ion (I-): Iodide ions are the most readily hydrolyzed among the halides. This is because iodine is the least electronegative halogen, and the I-H bond is relatively weak, making it easier for water molecules to break the bond and hydrolyze the iodide ion.

Bromide ion (Br-): Bromide ions are less readily hydrolyzed than iodide ions but more so than chloride ions. The Br-H bond is stronger than the I-H bond but weaker than the Cl-H bond, so hydrolysis occurs at an intermediate rate.

Chloride ion (Cl-): Chloride ions are the least readily hydrolyzed among the halides. The Cl-H bond is relatively strong, making it less susceptible to hydrolysis by water.

Fluoride ion (F-): Fluoride ions are generally not hydrolyzed under normal conditions. The F-H bond is strong, and fluoride ions tend to form stable complexes with water rather than undergoing hydrolysis.

Keep in mind that the actual rate of hydrolysis can also depend on other factors such as temperature, pH, and the presence of other ions or molecules in the solution.