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Acid and Base Definitions.ppt
The document provides detailed information on acids and bases, including their properties, definitions, and nomenclature. It outlines different theories such as Arrhenius, Brønsted-Lowry, and Lewis definitions of acids and bases, and discusses the behavior of amphoteric substances. Additionally, it gives examples of common acids and bases, highlighting their chemical characteristics and reactions.
Acid and Base Definitions.ppt
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- 4. Acids Have a sourtaste. Vinegar is a solution of acetic acid. Citrus fruits contain citric acid. React with certain metals to produce hydrogen gas. React with carbonates and bicarbonates to produce carbon dioxide gas Have a bitter taste. Feel slippery. Many soaps contain bases. Bases
- 5. Some Properties ofAcids Produce H+ (as H3O+) ions in water (the hydronium ion is a hydrogen ion attached to a water molecule) Taste sour Corrode metals Electrolytes React with bases to form a salt and water pH is less than 7 Turns blue litmus paper to red “Blue to Red ACID”
- 6. Anion Ending Acid Name -idehydro-(stem)-ic acid -ate (stem)-ic acid -ite (stem)-ous acid Acid Nomenclature Review No Oxygen w/Oxygen An easy way to remember which goes with which… “In the cafeteria, you ATE something Icky”
- 7. Acid Nomenclature Flowchart hydro- prefix -icending 2 elements -ate ending becomes -ic ending -ite ending becomes -ous ending no hydro- prefix 3 elements ACIDS start with 'H'
- 8. • HBr (aq) •H2CO3 • H2SO3 hydrobromic acid carbonic acid sulfurous acid Acid Nomenclature Review
- 9. Some Properties ofBases Produce OH- ions in water Taste bitter, chalky Are electrolytes Feel soapy, slippery React with acids to form salts and water pH greater than 7 Turns red litmus paper to blue “Basic Blue”
- 10. Some Common Bases NaOHsodium hydroxide lye KOH potassium hydroxide liquid soap Ba(OH)2 barium hydroxide stabilizer for plastics Mg(OH)2 magnesium hydroxide “MOM” Milk of magnesia Al(OH)3 aluminum hydroxide Maalox (antacid)
- 11. Acid/Base definitions • Definition1: Arrhenius (traditional) Acids – produce H+ ions (or hydronium ions H3O+) in water Bases – produce OH- ions in water (problem: some bases don’t have hydroxide ions!)
- 12. Arrhenius acid isa substance that produces H+ (H3O+) in water Arrhenius base is a substance that produces OH- in water
- 13. Acid/Base Definitions • Definition2: Brønsted Lowry Acids : proton donor Bases : proton acceptor A “proton” is really just a hydrogen atom that has lost it’s electron!
- 14. A Brønsted-Lowry acidis a proton donor A Brønsted-Lowry base is a proton acceptor acid conjugate base base conjugate acid
- 15. ACID-BASE THEORIES The Brønsteddefinition means NH3 is a BASE in water and water is itself an ACID Base Acid Acid Base NH4 + + OH- NH3 + H2O
- 16. Amphoteric Substances • Asubstance that is Amphoteric can act as either an acid or a base. • In the previous slide, water acted as an acid. • In the following example, water acts as a base. HCl (g) + H2O (l) H3O+ (aq) + Cl- (aq) acid base conj. acid conj. base
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- 18. Acid-Base Behavior • Considera compound having the formula HOX. • If X is highly electronegative, it will have a strong attraction for the electrons shared with O. o The O, will in turn, pull strongly on the electrons held shared with H. o This H will then be easily lost = acid • If X has a low electro negativity, the oxygen will pull the electrons away from X. o The hydrogen will remain joined to the oxygen. o Since the O and H can easily remain together, it is likely that OH- will be formed = base • Nonmetals tend to have high EN = acids • Metals tend to have low EN = bases
- 19. Acids & BaseDefinitions Lewis acid: A substance that accepts an electron pair Lewis base: A substance that donates an electron pair Definition 3: Lewis
- 20. Formation of hydroniumion is also an excellent example. Lewis Acids & Bases •Electron pair of the new O-H bond originates on the Lewis base. H H H BASE •• • ••• O—H O—H H+ ACID
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