Acid Base Reactions

Video about Arrhenius, Bronsted Lowry, and Lewis Acids and Bases.

Acid-base reaction (hydrolysis)

Consider an aqua-complex such as M(H₂O)₆²⁺.

Now think about one of the M - OH₂ coordinate bonds. Electron density will be pulled along the coordinate bond towards the metal ion.

Fortunately for the M²⁺ion this is a fairly small effect.

Supposing we think about this for a M³⁺ ion. The positive charge is larger and so the electron density s more attracted to the transition metal ion. If it is pulled strongly enough, it could break the O-H bond. This would release a H⁺ ion. This is especially likely to happen if there is a base handy to grab hold of the H⁺ions.

Consequently, M³⁺ ions are considered to be acidic.