1. Acids and Bases

2. Arrhenius Theory Acids produce H + ions. Acids produce H + ions. Bases produce OH - ions. Bases produce OH - ions. HCl  H + + Cl - NaOH  Na + + OH - NaOH  Na + + OH -

3. Bronsted-Lowry Theory Acids donate protons Acids donate protons Bases accept protons Bases accept protons HCl(g) + H 2 O(l)  H 3 O + (aq) + Cl - (aq) HCl(g) + H 2 O(l)  H 3 O + (aq) + Cl - (aq) acid base acid base Acid + base  conjugate base + conjugate acid conjugate acid conjugate base

4. Neutralization NH 3(g) + H 2 O(l)  NH 4 + (aq) + OH - (aq) NH 3(g) + H 2 O(l)  NH 4 + (aq) + OH - (aq) A conjugate base is formed when an acid gives up its proton. A conjugate base is formed when an acid gives up its proton. A conjugate acid is formed when a base accepts a proton. A conjugate acid is formed when a base accepts a proton. baseacid conjugate acid conjugate base

5. Lewis Theory Acids accept an electron pair (must have an empty orbital) Acids accept an electron pair (must have an empty orbital) Bases donate an electron pair (must have at least one filled orbital) Bases donate an electron pair (must have at least one filled orbital) H H + H H + H N H + H-O-H H N H + OH - H N H + H-O-H H N H + OH - H H

6. All acids and bases discussed so far are Lewis acids and bases. All acids and bases discussed so far are Lewis acids and bases. Now we have some new possibilities... Now we have some new possibilities... H F H F H F H F H N:+ B F  H N B F H F H F H F H F Lewis base Lewis acid

7. amphoteric A substance that can act as an acid or a base. A substance that can act as an acid or a base. Water: HCl + H 2 O  H 3 O + + Cl - Water: HCl + H 2 O  H 3 O + + Cl - acid base acid base NH 3 + H 2 O  NH 4 + + OH - NH 3 + H 2 O  NH 4 + + OH - base acid base acid

8. Anhydrides- acids or bases that have had water removed Anhydrides- acids or bases that have had water removed Acidic anhydrides- produce an acid when dissolved in water Acidic anhydrides- produce an acid when dissolved in water Acid rain: SO 2 (g) + H 2 O(l)  H 2 SO 4 (aq) Basic anhydride- produces a base when dissolved in water Basic anhydride- produces a base when dissolved in water Na 2 O(s) + H 2 O(l)  2NaOH(aq)

9. If a metal oxide, a base will form If a metal oxide, a base will form If a nonmetal oxide, an acid will form If a nonmetal oxide, an acid will form Write the formula for the anhydride of HNO 3 We must remove an H 2 O. We must remove an H 2 O. 2HNO 3 – H 2 O  N 2 O 5 Complete the following equation: CaO + H 2 O  CO 2 + H 2 O  Ca(OH) 2 H 2 CO 3

10. Strong acids ionize completely HCl HBr HBr HI HI H 2 SO 4 HNO 3 HClO 3 HClO 3 HClO 4 HClO 4 The stronger an acid, the weaker its conjugate base and visa versa.

11. Polyprotic acids - have more than one hydrogen to ionize - Ex: H 2 SO 4 – the second or third H + ionizes weakly

12. Strong bases KOHNaOH Mg(OH) 2 (low solubility, but dissociates) Ca(OH) 2 Ca(OH) 2 -the hydroxides of alkali metals and heavy alkali earth metals heavy alkali earth metals

13. Naming acids anion acid nameexample -ide Hydro- icHCl hydrochloric acid -ite -ousHNO 2 nitrous acid -ate -icHNO 3 nitric acid

14. Try these H 2 SO 4 H 2 SO 4 HF HF H 3 PO 4 H 3 PO 4 H 2 SO 3 H 2 SO 3 H 2 CO 3 H 2 CO 3 HNO 3 HNO 3 sulfuric acid hydrofluoric acid phosphoric acid sulfurous acid carbonic acid nitric acid

15. hydrolysis The reaction of a salt with water to form an acidic or basic solution. The reaction of a salt with water to form an acidic or basic solution. cationanionsolution Strong base Strong acid Neutral Strong base Weak acid Basic Weak base Strong acid Acidic Weak base Weak acid Neutral

16. Strong bases: Strong bases: hydroxides of groups 1 & 2 (except Be) Strong acids: Strong acids: HCl, HBr, HI HClO 3, HClO 4, H 2 SO 4, HNO 3

17. NaCl NaCl produces a neutral solution produces a neutral solution CuSO 4 CuSO 4 produces an acidic solution produces an acidic solution K 2 CO 3 K 2 CO 3 produces a basic solution produces a basic solution From NaOH, strong base From HCl, strong acid A weak base H 2 SO 4, strong acid KOH, Strong base Weak acid