Lewis Acid Base Theory B Lewis acid Lewis base Two electron covalent bond Electron-pair acceptor, Electron-pair Lewis Acid/Base Vacant orbital · EXamples Cao So Caso H++OH→HOH Lewis calcium base acid sulphate Proton transfer to alcohols H H HN计+BF→HN:BR∧ Br H Lewis id Base Acid Conjugate Conjugate 8Lewis Acid & Base Theory z Examples 8