In terms of molecular structure, what factor increases the stability of a conjugate base?

The stability of a conjugate base is significantly influenced by the electronegativity of the atoms involved. When a molecule donates a proton (H+), the resulting conjugate base bears a negative charge. The distribution and stability of this negative charge depend heavily on the electronegativity of the atom that holds it.

Atoms that are more electronegative can better stabilize negative charges. This is because they have a greater ability to attract and hold onto electrons due to their higher electronegativity values. Therefore, if the conjugate base has a negatively charged atom that is more electronegative, that negative charge will be more stable and less reactive compared to a conjugate base with a less electronegative atom holding the charge.

For instance, consider the conjugate bases of strong acids like hydrochloric acid (Cl-) versus acetic acid (CH3COO-). The chloride ion (Cl-) is stabilized by the electronegativity of chlorine, while the acetate ion (CH3COO-) is stabilized by resonance, which also reflects the distribution of electronegativity across both oxygen atoms.

Other factors listed, such as the weight of the molecule, geometric arrangement, and phase, have less direct influence on the fundamental