Determining strength of acids

[Brooke Gushiken 1B]

Hi! I was wondering how we can determine which acid is stronger when comparing, for example, HF vs. HCl. What factors should we take into account when comparing and drawing a conclusion? Thank you!

[Ella Henrickson 3I]

Hello! Overall, the stronger an acid the more easily it loses H+ and the more stable the resulting anion.

H+ : This can be determined by looking at bond strength since the weaker a bond is the more likely it is to lose an H+.

Stability: If the resulting anion is stabilized by resonance structures and/or electron-withdrawing atoms which both delocalize and stabilize the negative charge.

[Naman Jain 3F]

Hi! In the example you provided, HCl would be the stronger acid. This is because fluorine is more electronegative compared to chlorine leading to a stronger and shorter bond in HF compared to HCl. This means that HF is less likely to lose an H+ due to its stronger bond, making it less acidic effectively.

[Mason_Hoppe_1A]

As the above answers outlined, a good way to determine the strength of an acid is to go off of bond strength. Visually, you can follow the same trend in the periodic table that dictates bond length, where the longer the bonds (and atomic radii), the stronger the acid.

[Kurosh Zamiri 1I]

Hi! The stronger acid is the acid that more easily loses its H+ ion. Therefore, the molecule with the weakest bonds would lose its proton easier. In this case, since fluorine is the most electronegative element, it holds onto the H+ much more tightly than the chlorine would. Due to this, HF is a weak acid, while HCl is a strong acid. Hope this helps!

[Natasha]

Based on the example that you listed and similarly to what other people have been saying since fluorine is more electronegative it has a stronger bond in HF compared to HCL which makes HF less acidic.

[LukeYing_3H]

The strength of an acid is measured by it's tendency/ability to donate/lose H+ ions

[August Blum Dis 3D]

Acids are stronger if they can dissociate better. Since the HCl bond is weaker than the HF bond, it is thus a stronger acid.