Question

what is Lewis acid explain

Answer 1

electron pair acceptor is lewis acid

Answer 2

In 1923 G. N. Lewis suggested another way of looking at the reaction between H+ and OH- ions. In the Brnsted model, the OH- ion is the active species in this reaction  it accepts an H+ ion to form a covalent bond. In the Lewis model, the H+ ion is the active species
it accepts a pair of electrons from the OH- ion to form a covalent bond.