Acids and Bases

Properties electrolytes turn litmus red sour taste react with metals to form H 2 gas slippery feel turn litmus blue bitter taste ChemASAP vinegar, milk, soda, apples, citrus fruits ammonia, lye, antacid, baking soda electrolytes

Acid vs. Base Acid pH > 7 bitter taste does not react with metals pH < 7 sour taste react with metals Alike Different Related to H + (proton) concentration pH + pOH = 14 Affects pH and litmus paper Base Different Topic

Common Acids and Bases Strong Acids (strong electrolytes) HClhydrochloric acid HNO 3 nitric acid HClO 4 perchloric acid H 2 SO 4 sulfuric acid Weak Acids (weak electrolytes) CH 3 COOHacetic acid H 2 CO 3 carbonic Strong Bases (strong electrolytes) NaOH sodium hydroxide KOH potassium hydroxide Ca(OH) 2 calcium hydroxide Weak Base (weak electrolyte) NH 3 ammonia Kotz, Purcell, Chemistry & Chemical Reactivity 1991, page 145 Weak Base (weak electrolyte) NH 4 OH ammonia NH 3 + H 2 O  NH 4 OH

Common Acids Sulfuric AcidH 2 SO 4 Nitric AcidHNO 3 Phosphoric AcidH 3 PO 4 Hydrochloric AcidHCl Acetic Acid CH 3 COOH Carbonic Acid H 2 CO 3 Battery acid Used to make fertilizers and explosives Food flavoring Stomach acid Vinegar Carbonated water

Common Bases Sodium hydroxideNaOHlye or caustic soda Potassium hydroxideKOHlye or caustic potash Magnesium hydroxideMg(OH) 2 milk of magnesia Calcium hydroxideCa(OH) 2 slaked lime Ammonia waterNH 3 H 2 Ohousehold ammonia Name Formula Common Name. NH 4 OH NH OH 1- ammonium hydroxide hydroxide ion OH 1-

Formation of Hydronium Ions 1+ hydronium ion H3O+H3O+ + hydrogen ion H+H+ water H2OH2O 1+ (a proton) 1+

Arrhenius Acid hydronium ion H3O+H3O+ 1- chloride ion Cl - water H2OH2O hydrogen chloride HCl (an Arrhenius acid) Any substance that releases H + ions as the only positive ion in the aqueous solution.

Arrhenius Bases and Their Properties According to the definition of Arrhenius a: Base Base - "a substance whose water solution yields... Are NaOH and NH 3 considered to be Arrhenius bases? 1) Bases are electrolytes Dissociation equation for NH 3 NH 3 (g) + H 2 O(l) NH 4 1+ (aq) + OH 1- (aq) Dissociation equation for NaOH NaOH(s) Na 1+ (aq) + OH 1- (aq) indicators 2) Bases cause indicators to turn a characteristic color 3) Bases neutralize acids NaOH(aq) + HCl(aq) NaCl(aq) + H 2 O(l) YES 4) Water solutions of bases tasted bitter and feel slippery. hydroxide ions (OH - ) as the only negative ions."

Each of the following unbalanced equations represents a reaction between a Arrhenius acid and base. Identify those in each reaction: H 2 CO 3 + NH 4 OH → (NH 4 ) 2 CO 3 + H 2 O KOH + H 3 PO 4 → K 3 PO 4 + H 2 O HF + NaOH → NaF + H 2 O Ba(OH) 2 + HNO 2 → Ba(NO 2 ) 2 + H 2 O

Brønsted-Lowry Acids and Bases 1+ + hydronium ion H3O+H3O+ 1- chloride ion Cl - (base) H2OH2O (acid) HCl ++ -- Acid = any substance that donates a proton. Base = any substance that accepts a proton.

Brønsted-Lowry Acids and Bases 1+ + hydronium ion H3O+H3O+ 1- chloride ion Cl - (base) H2OH2O (acid) HCl ++ -- Acid = any substance that donates a proton. Base = any substance that accepts a proton.

Brønsted-Lowry Acids and Bases (acid) H2OH2O (base) NH 3 ++ - ammonium ion NH hydroxide ion OH -

Identify the Bronsted-Lowry acid and the Bronsted-Lowry base in each reaction. NH 4 + (aq) + CN - (aq) → HCN (aq) + NH 3 (aq) (CH 3 ) 3 N(aq) + H 2 O → (CH 3 ) 3 NH + (aq) + OH - (aq) HCHO 2 (aq) + PO 4 3- → CHO 2 - (aq) + HPO 4 2- (aq) HSO 4 - (aq) + CO 3 2- → SO 4 2- (aq) + HCO 3 - (aq)

Definitions  Lewis AcidsAcids are electron pair acceptors. BasesBases are electron pair donors. Lewis base Lewis acid Courtesy Christy Johannesson

Arrhenius Acids and Bases Acids release hydrogen ions in water. Bases release hydroxide ions in water. An acid is a substance that produces hydronium ions, H 3 O +, when dissolved in water. Lewis Definitions A Lewis acid is a substance than can accept (and share) an electron pair. A Lewis base is a substance than can donate (and share) an electron pair. Lewis Acid Brønsted-Lowry Definitions A Brønsted-Lowry acid is a proton donor; it donates a hydrogen ion, H +. A Brønsted-Lowry base is a proton acceptor; it accepts a hydrogen ion, H +. Brønsted-Lowry Arrhenius acids Acid Definitions

Lewis acids Brønsted-Lowry Arrhenius acids The Arrhenius model of acids and bases was broadened by the Brønsted-Lowry model. The Lewis acid-base model is the most general in scope. The Lewis definition of an acid includes any substance that is an electron pair acceptor; a Lewis base is any substance that can act as an electron pair donor. Ralph A. Burns, Fundamentals of Chemistry 1999, page 483

Lewis acids Brønsted-Lowry Arrhenius acids The Arrhenius model of acids and bases was broadened by the Brønsted-Lowry model. The Lewis acid-base model is the most general in scope. The Lewis definition of an acid includes any substance that is an electron pair acceptor; a Lewis base is any substance that can act as an electron pair donor. Ralph A. Burns, Fundamentals of Chemistry 1999, page 483 Acid Definitions

Acid – Base Systems TypeAcidBase ArrheniusH + or H 3 O + producer OH - producer Brønsted- Lowry Proton (H + ) donor Proton (H + ) acceptor LewisElectron-pair acceptor Electron-pair donor