Lewis theory of acids and bases?

Answer 1

Lewis acid is an electron acceptor / Lewis base is an electron donor. It is helpful to use this definition of acid and base in (1) organic chemistry (2) also when there are no Hydrogens present in the molecule. BF3 is a Lewis acid it seeks out and can accept electrons.

Answer 2

There's basically 3 different definitions for acids and bases...since noone can really decide what they are. They're all correct and often overlap.

Standard definition ([H+] rise/[OH-] rise)

Lewis definition (Lone pair acceptor/donor)

Bronsted-Lowry definition (H acceptor/donor)

The Lewis theory says that acids are lone pair acceptors and bases are lone pair donors.

So if we say something "acts like a Lewis acid" it means it's accepting a lone pair (of electrons, that is!) in that reaction. It's a great way of describing a molecule's role in the reaction just by referring to it.

It's worth mentioning that if we have the reaction:

A + B ---> C + D

If A is a Lewis acid, then B must be a Lewis base. (If A is accepting a pair of electrons...it's gotta get them from somewhere and B is the only other thing there, so B must be a lone pair donor).

As a final note, it's important to remember that here no molecule is always an acid or always a base. The words acid and base simply describe how that molecule acts in the reaction...it's the role it plays rather than a permanent property of the molecule itself.

If you're unsure what a lone pair is, now is the time forget acids and bases and take a moment to learn that first.

Answer 3

In Lewis theory, an acid is a species that accepts a pair of electrons to form a covalent bond, while a base is a species that donates a pair of electrons to form a covalent bond. This theory expands the concept of acids and bases beyond just proton transfer, as seen in the Brønsted-Lowry theory. Lewis acids can accept electron pairs from bases to form coordinate covalent bonds.

Answer 4

What is Lewis' acidWhat is Lewis' acids and basess and bases