Acidbase#1
- 1. LEWIS ACID BASE THEORYNadia and Vito
- 2. acidA substance which produces hydrogen ions, H+, when it is dissolved in water.Properties: Acids have a sour taste.Acids dissolve in water to form solutions which conduct electricity. Acids turn blue litmus paper red. Acids react with reactive metals to form hydrogen and a salt.Acids react with carbonates to form a salt, carbon dioxide and water. Acids react with bases to produce a salt and water only.
- 3. base - alkaliBase is any metal oxide or hydroxide – it contains either oxide ions, O2-, or hydroxide ions, OH-. Alkali is a base that is soluble in water. Properties:Alkalis have a bitter taste and soapy feel. Alkalis turn red litmus paper blue. Alkalis produce hydroxide ions when dissolved in water. All alkalis can react with acids to form a salt and water only
- 4. the lewis acid base theoryThe Lewis Acid Base Theory suggests an acid as the reactant that receives an electron pair from another reactant in a chemical reaction, and a base as the reactant that that donates an electron pair to another reactant.In a Lewis Acid-Base reaction, the base donates an electron pair, forming a coordinate covalent bond joining the two species together into the reaction product.
- 5. lewis acids and basesA Lewis acid is a any substance that can accept a pair of nonbonding electrons. Lewis acids are electron-pair acceptors.All cations.All molecules possessing an atom with incomplete octet.A Lewis base is any substance that can donate a pair of nonbonding electrons. Lewis bases are electron-pair donors. All anions.All molecules having lone-pairs of electrons.
- 6. lewis acid base reactionFrom the definition of acid and base suggested by Lewis, we can write acid-base reactions like this:Characteristics of these reactions:They are charge balanced – the total charge of all species is the same on both sides.The product is sometimes described as a Lewis “complex”.Red arrows are used to show the how the bond between the acid and base is formed.The tail sits on a pair of electrons.The head sits on points to where these electrons will be in the product.
- 7. homo-lumoIn modern theoretical language:the Lewis base’s filled orbital is the highest occupied molecular orbit – or HOMO.The Lewis acid’s empty orbital is the lowest unoccupied molecular orbit – or LUMO. We refer to the interaction as the “filled-empty” interaction or the “HOMO-LUMO” interaction.
- 8. example of reactionBF3 + NH3 ? Consider the molecules BF3 and NH3. If we determine the Lewis structure of BF3 and NH3, we find that B is octet deficient and can accept a lone pair. While N is capable of donating a lone pair. N donates a pair of electrons to B, creating a coordinate covalent bond between them.Acid Base Lewis Complex
- 9. Predict whether the following ions or molecules can act as either a Lewis acid or a Lewis base. Ag+NH3