2. Acids, Bases, and Salts

3. I. Properties of Acids n Sour taste n Change colors of acid-base indicators warm colors– turns litmus paper red n Some react with active metals to release H 2 Acid + Base → Salt + water Acid + Base → Salt + water n Conduct electric current

4. III. Properties of Bases n Bitter taste n Change colors of acid-base indicators cool colors– turns litmus paper blue n Feel slippery n React with acids to produce salts and water n Conduct electric current

5. Write dissociation equation & balance 1. HCl → 2. HNO 3 → 3. NaOH → 4. Mg(OH) 2 → 5. NaCl → Note any similarities between the equations

6. IV. ARRHENIUS THEORY n Acids, n Acids, bases, and salts conduct a current when dissolved in water - electrolytes n An n An acid produces H+ in a water solution HCl(g) --> --> H+(aq) H+(aq) + Cl-(aq) n A n A base produces OH- in a water solution NaOH(cr) --> Na+(aq) + OH-(aq)

7. II. Naming Acids - Binary n Binary acid – contains 2 elements; hydrogen and one of the more electronegative elements. n Ex. HF 1. Begins with prefix hydro 2. Followed by root of name of second element 3. Ends with suffix -ic hydro – fluor – ic acid nH2SnH2SnH2SnH2S

8. II. Naming Acids - oxyacids n Compound of hydrogen, oxygen, and a 3 rd element that is usually a nonmetal n Formula is usually one or more H atoms followed by polyatomic anion n Pg. 250 n HNO 2 – nitrous acidNO 2 - nitrite n HNO 3 – nitric acidNO 3 - nitrate n Common industrial – sulfuric, nitric, phosphoric, hydrochloric, acetic

9. Practice problems n Pg.250 #’s 18-22 n Pg. 596 1a,1b

10. Strong vs. weak n Strong acids and bases fully dissociate n Weak acids and bases partially dissociate

11. V. BRONSTED-LOWRY THEORY n Acid – proton (H+) donor Base – proton acceptor n The conjugate base of an acid is the particle that remains after a proton is released by the acid. n The conjugate acid of a base is formed when the base receives a proton from an acid. In the reaction NH 3 (g) + water(l)->NH 4 + (aq) + OH-: NH 3 is the base, water is the acid, NH4+ is the conjugate acid, and OH- is the conjugate base. In the reaction NH 3 (g) + water(l)->NH 4 + (aq) + OH-: NH 3 is the base, water is the acid, NH4+ is the conjugate acid, and OH- is the conjugate base. N H H H O H H N HH H H O H

12. PRACTICE PROBLEMS Which is the conjugate base / conjugate acid in: H 3 PO 4 H 3 PO 4 + H 2 O H 2 O --> H3O+ H3O+ H3O+ H3O+ + H 2 PO 4 - H 3 O H 3 O is the conjugate acid acid and H 2 PO 4 H 2 PO 4 is the conjugate base. One more, which is the conjugate base / conjugate acid in: H4P2O7 H4P2O7 H4P2O7 H4P2O7 + H 2 O H 2 O --> H3O+ H3O+ H3O+ H3O+ + H3P2O7-H3P2O7-H3P2O7-H3P2O7- Again H 3 O H 3 O is the conjugate acid acid and H 3 P 2 O 7 - H 3 P 2 O 7 - is the conjugate base.

13. BRONSTED-LOWRY Acid Base Reactions n HF + H 2 O → F- + H 3 O + n Subscripts designate 2 conjugate acid base pairs n HF + H 2 O → F- + H 3 O + acid 1 base 2 base 1 acid 2 acid 1 base 2 base 1 acid 2 n Strength of conjugate acid and base – strong acid – weak conj. Base. Reactions favors direction that produces weaker acids and bases

14. Amphoteric n Can act as acid or base (H 2 O) n H 2 SO 4 + H 2 O → base base n NH 3 + H 2 O → acid acid

15. BRONSTED-LOWRY THEORY n Monoprotic acid – donates only one proton n Polyprotic acid – donates more than one proton Diprotic – donates 2 protons Triprotic – donates 3 protons n All polyprotic ionize in steps n H 3 PO 4 (aq) pg. 601 #3a,3b

16. LEWIS THEORY n Lewis n Lewis focused on an electron transfer rather than a proton transfer. described an acid as an electron-pair acceptor and a base as an electron-pair donor. n An n An acid or base in Arrhenius theory is the same under the Lewis and Bronsted-Lowry theories.

17. MORE PRACTICE PROBLEMS n CLASSIFY THE FOLLOWING SUBSTANCES AS LEWIS ACIDS OR BASES. a. Cl- b. Al+ c. Br- d. I+ a and c = Lewis Base b and d = Lewis Acid