HCl is more acidic than HF
The acidic strength of hydrogen halide depends on the following factors:
1.Degree of dissociation
( How easily it will donate H+ ions)
Note:Acid is a substance that will donate H+ ions
More degree of dissociation = more acidic
Less degree of dissociation = less acidic
2. Type of bonding
Although all hydrogen halide has a covalent bond. Hf has a special type of bonding. i.e. Hydrogen bonding.
Due to H-bonding, HF is least acidic than HCl, HBr & HI.
The hydrogen atom in HF is entrapped between two fluorine atoms & not easily available as proton(H+).
Increasing acidic order: HF ＜ HCl ＜ HBr ＜ HI