Having a hard time distinguishing between an acid and a lewis acid? Check the answer below and get the clear-cut difference.
A Lewis acid is defined as an electron-pair acceptor, whereas a Lewis base is an electron-pair donor. Under this definition, we need not define an acid as a compound that is capable of donating a proton, because under the Lewis definition, H+ itself is the Lewis acid; this is because, with no electrons, H+ can accept an electron pair.
Lewis Acids are the chemical species which have empty orbitals and are able to accept electron pairs from Lewis bases. This term was classically used to describe chemical species with a trigonal planar structure and an empty p-orbital.
As for a Lewis base, it is a chemical species having a highly localised Occupied Molecular Orbital.
To put it somple, a Lewis acid is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct.
Examples of Lewis acids include; H+ ions (or protons), cations of d block elements with Fe3+, Metal cations like Mg2+ and Li+, etc.