HF weaker acid than HCl?

[PlentyOLulz]

Why is HF a weaker acid than HCl?

I thought HF was more Polar/Electronegative, so it would be a stronger Acid?

---

Members don't see this ad.

 

[Aljazera]

Smaller orbital which causes it to be harder to dissociate compared to other Halogens.

 

[inaccensa]

Why is HF a weaker acid than HCl?

I thought HF was more Polar/Electronegative, so it would be a stronger Acid?

Strength of acids - Strength of the bond, polarity of the bond and the stability of the conjugate base.

HF is indeed more polar than HCl, but the stability of the conjugate base is more imp when measuring the strength of acids. The basicity trends increases as F->Cl>Br->I-,so if HF were to dissociate F- will spontaneously react with H+,whereas I- is relatively stable..thats how i think of it

 

[PlentyOLulz]

ahhhhhhh

great responses thanks

Just got a bit confused.

 

[boaz]

Why is HF a weaker acid than HCl?

I thought HF was more Polar/Electronegative, so it would be a stronger Acid?

Here's what I answered a while ago to a similar question:

The true underlying reason is that a bond is basically an electrostatic attraction. As we know from physics the force of this attraction is governed by Coulomb's Law: F=Kqq/r^2. Since the radius of F- is much smaller than that of Cl-, the H-F bond is smaller than H-Cl. This means that r^2 is much smaller in H-F than in H-Cl. From the equation, as r becomes smaller, F becomes larger, hence the stronger bond.