Courses
Courses for Kids
Free study material
Offline Centres
More Last updated date: 04th Dec 2023
Total views: 281.4k
Views today: 7.81k

# AssertionIncreasing order of acidity of hydrogen halides is $HF < HCL < HBr < HI$ReasonWhile comparing acids formed by the elements belonging to the same group of periodic table, $H - A$ bond strength is a more important factor in determining acidity of an acid than the polar nature of the bond.$A)$Both Assertion and Reason are correct and Reason is the correct explanation for Assertion$B)$ Both Assertion and Reason are correct but Reason is not the correct explanation for the Assertion$C)$Assertion is correct but Reason is incorrect $D)$Both Assertion and Reason are incorrect Verified
281.4k+ views
Hint: It depends on the strength of the $H - A$ bond. The weaker the bond, the lesser the energy required to break it. Hence, the acid is strong. The polarity of the $H - A$ bond affects its acid strength.

The bond strength of an acid generally depends on the size of the $'A'$ atom: the smaller the $'A'$ atom, the stronger the $H - A$ bond. When going down a row in the Periodic Table, the atoms get larger so the strength of the bonds get weaker, which means the acids get stronger.
While comparing acids formed by the elements belonging to the same group of periodic table, $'A'$ bond strength is a more important factor in determining acidity of an acid than the polar nature of the bond.
So, the correct option is $A)$ Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Additional Information: Factors that affect the acidity:
$-$Charge - Removal of a proton, decreases the formal charge on an atom or molecule by one unit.
$-$Role of an atom.
$-$Resonance - A huge stabilizing factor for a conjugate base is if the negative charge can be delocalized through resonance.
$-$ Inductive effect - Electronegative atoms can draw negative charge toward themselves, which can lead to considerable stabilization of conjugate bases.
$-$ Orbitals - the acidity relates nicely to the stability of the conjugate base.

Note:
Fluorine is the most electronegative element and $H$ is the most electropositive element, $HF$ is the most polar. Hydrofluoric acid is chemically classified as a weak acid due to its limited ionic dissociation in ${H_2}O$ at${25^ \circ }$. In water at equilibrium, non-ionized molecules,$HF$, remain present and slowly ${H^ + }$ and ${F^ - }$ to form $F - {H_3}O$.