HCl vs. HBr

[Cecilia Cisneros 1F]

Is HCl or HBr the stronger acid? Dr. Lavelle said that HBr is the stronger acid, but the bond between HBr is longer than the bond between HCl. Longer bonds are weaker bonds. So now I'm not sure how HBr can be stronger than HCl.

[Kaley Qin 1F]

Due to it's longer bond length, HBr can completely ionize more easily than HCl, meaning HBr can produce more H+ ions than HCl. Since acid strength is based on the number of protons produce, HBr is stronger than HCl.

[Shrey Pawar 2A]

Just to reinforce what was stated above, being a stronger acid or base does not necessarily have to do with the strength of a bond as much as the acids ability to ionize. In this case, because HBr would have a weaker bond it can more easily ionize and is the stronger acid. Hope this helps!

[Andrew Wang 1C]

So would it be true to say that the weaker the bond, the stronger the acid since it dissociates more easily?

[Janelle Gokim 3B]

I think that is reasonable to say. That seemed to be the point Dr. Lavelle was making in lecture, that because HBr has a longer and therefore weaker bond, it could ionize more easily in water.

[Marisa Gaitan 2D]

So would it be true to say that the weaker the bond, the stronger the acid since it dissociates more easily?

I think so, and that is also why HF is a weak acid since it has a shorter and therefore stronger bond than HCl and HBr.

[Emmeline Phu 1G]

Hi! The HBr bond is longer than HCl but when we are determining the strength of acids we are looking at its ability to ionize or dissociate in a solution. If the bond is weaker in a molecule, it is able to ionize easily (produce more H+ ions) whereas if a bond is stronger it is not able to do so. Strong acids are characterized by its ability to almost completely ionize or dissociate in a solution; therefore, since HBr is able to ionize more easily than HCl, it is a stronger acid. Hope this helps! :)