1. Unit 3 Acids and Bases

2. 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

3. Sulfuric Acid, H 2 SO 4 Sulfuric acid is the most commonly produced industrial chemical in the world. Uses: petroleum refining, metallurgy, manufacture of fertilizer, many industrial processes: metals, paper, paint, dyes, detergents Sulfuric acid is used in automobile batteries. H 2 SO 4 “oil of vitriol”

4. Nitric Acid, HNO 3 Nitric acid stains proteins yellow (like your skin). Uses: make explosives, fertilizers, rubber, plastics, dyes, and pharmaceuticals. HNO 3 “aqua fortis”

5. Hydrochloric Acid, HCl The stomach produces HCl to aid in the digestion of food. Uses: For ‘pickling’ iron and steel. Pickling is the immersion of metals in acid solution to remove surface impurities. A dilute solution of HCl is called muriatic acid (available in many hardware stores). Muriatic acid is commonly used to adjust pH in swimming pools and in the cleaning of masonry. HCl(g) + H 2 O(l) HCl(aq) hydrogen chloride water hydrochloric acid

6. 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

7. Naming Bases Bases are ionic compound. They follow the rules for naming ionic compounds and you have to use criss cross method to write the chemical formula. (The “+” ion first followed by the “-” ion.) Ex. 1 sodium hydroxide Na + OH - NaOH

8. Naming Bases Ex. 2 KOH K+K+ OH - Potassium hydroxide

9. Naming Acids and writing formulas for acids Acids donate hydrogen ions (H + ) and their chemical formulas have a hydrogen written at the beginning. Names of acid depend on the negative ion and its ending. (handout with rules was given in class)

10. Acids properties 1. Conduct electricity (strong acids) 2. Change blue litmus to red 3. Have a sour taste 4. React with bases to neutralize their properties 5. React with active metals to liberate hydrogen 6. pH values <7

11. Acids Acids are defined as: Substances which ionize to form hydrogen ions (H + ) in aqueous solution. (Arrhenius) Substances that act as proton donors, H + (Bronsted- Lowry) or as electron-pair acceptors (Lewis) Examples HCl, H 2 SO 4

12. Bases properties Base properties 1. Conduct electricity (strong bases) 2. Change red litmus to blue 3. Have a slippery feeling (like soap) 4. React with acids to neutralize their properties 5. pH values >7

13. Bases Bases are defined as: Substances which ionize to form hydroxide ions OH(-) in aqueous solution Substances that act as proton receptors (Bronsted-Lowry) or as electron-pair donors (Lewis) Examples: NH 3 OH, NaOH, CaCO 3, NaHCO 3 (baking soda) AMMONIA cleaner

14. pH Scale The pH scale is used to measure how acidic or basic a liquid is. pH measures the concentration of hydrogen ions (H+) and hydroxide ions (OH-). The scale goes from 0 through 14. Distilled water is 7, so is called neutral. lemon juice 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 pH Acidic Neutral Basic vinegar d water baking soda ammonia detergent

15. Indicators IndicatorAcidBase Red litmus paperStays sameTurns blue Blue litmus paperTurns redStays same Bromophenol blueYellowStays blue PhenolphtaleinColorlessPink An indicator is a large organic molecule that works somewhat like a "color dye."

16. Natural indicators There are natural indicators for acids and bases, and we may find them in our kitchen or garden! Red rose flowers Bougainvillea flowers Red cabbage Blue berries

17. Practice: identifying acid and bases 1) HCl + H2O  H3O + + Cl – HCl is the acid because it is donating a H + to H 2 O H 2 O is the base because it is accepting a H + from HCl Cl - is the conjugate base because it’s what’s left after the acid donates a H + H+H+ H 3 O + is the conjugate acid because it’s what’s left after the base accepts a H +

18. Practice: identifying acid and bases 2) CN - + H2O  OH - + HCN H 2 O is the acid because it is donating a H + to CN - CN - is the base because it is accepting a H + from H 2 O OH - is the conjugate base because it’s what’s left after the acid donates a H + H+H+ HCN is the conjugate acid because it’s what’s left after the base accepts a H +

19. Practice: identifying acid and bases 3) OH - + HI  H+H+ The acid can donate a H + and its chemical formula usually has a H at the beginning acid Donates a H + H2OH2O+ I-I- Classwork :handout conjugate acids and bases