Electronegativity and acidity

[Andrew Hong]

How do electronegativity and acidity relate?

[Kay Manzano 1K]

The stronger the attraction, the higher the electronegativity. By taking this theory a step further, we may deduce that atoms with greater electronegativity will be less likely to give up an electron to a proton. Therefore, basicity will decrease as the electronegativity of the atom sharing the electron pair increases. We conclude that when an atom's electronegativity increases, so does the acidity of the connected proton since weaker bases have stronger conjugate acids.

[Levy Shaked]

Another way of approaching this is that if the non-proton component of the acid (Cl- in HCl, ClO4- in HClO4, etc) is more electronegative and has a stronger affinity for electrons, it will draw the acidic hydrogen's electron closer to it and way from the hydrogen itself. This will polarize the hydrogen atom and cause it to develop a stronger partial charge, making its non-covalent interactions with external partial negative charges more stable. This increases the likelihood that the proton will be released and instead bind to that external partial negative charge.