Question

Explain why HFis a weak acid, whereas$\mathbf{HCl}\mathbf{,}\mathbf{}\mathbf{HBr}$, and HIare all strong acids.

Short answer

Hydrofluoric acid is a weak acid due to its limited ionic dissociation in${\mathrm{H}}_2\mathrm{O}$ at $25°\mathrm{C}$.

Step-by-step solution

Define Weak Acids

Weak Acids are the acids that fail to dissociate into their constituent ions when dissolved in solutions completely

Explanation of why HF is weak acid than others

Hydrofluoric acid (HF) is chemically known as a weak acid due to its limited ionic dissociation in${\mathrm{H}}_2\mathrm{O}$ at $25°\mathrm{C}$.

Due to hydrofluoric acid being a weak acid, it does not completely dissociate into its ions in water.

Since the bond between HF is stronger than the bond between HCl.

HCl will dissociate more completely, which makes it a stronger acid.

As we go through Group 7A, the bond between hydrogen and halogen weakens.

This only causes easier dissociation.

Therefore, Hydrofluoric acid is said to be a weak acid due to its limited ionic dissociation in ${\mathrm{H}}_2\mathrm{O}$at $25°\mathrm{C}$.