Among halide ions, iodide is the most powerful reducing agent
Fluorine is the only halogen that does not show a variable oxidation state
$\mathrm{HOCl}$ is a stronger acid that $\mathrm{HOBr}$
$\mathrm{HF}$ is a stronger acid than $\mathrm{HCl}$
Solution
$\mathrm{HCl}$ is a stronger acid than $\mathrm{HF}$ because fluorine is more electronegative than chlorine. Hence, it does not lose $\mathrm{H}^{+}$ easily.
Caution
$H F$ is a weak acid because the bond between Hydrogen and Fluorine is so short. It is more difficult for the bond to be broken, so it will not completely dissociate in water.