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Slide 2 VOCABULARY TERMS: IONIZATION Atoms can gain or lose electrons in order to form ions DISSOCIATION When ionic compounds dissolve in water, their ions separate from one another Slide 3 Steve Spangler Acids and Bases Youtube Slide 4 Slide 5 Ionization of Water youtube Ionization of Water youtube (29 secs) H+ will quickly attach to another water molecule Slide 6 What determines if it is becoming an acid or a base? Slide 7 Slide 8 Slide 9 Dissociation of Water Podcast (2:37) southern accent Dissociation of Water Podcast reversible Slide 10 Slide 11 Slide 12 Equilibrium constant Slide 13 What is Kw? Kw is essentially just an equilibrium constant for the reactions shown. You may meet it in two forms: Based on the fully written equilibrium...... or on the simplified equilibrium: Slide 14 FYI A hydrogen ion is also just a proton. Slide 15 Nice Nerdy Explanation Dissociation of Water (youtube 4:33) Dissociation of Water Nice Nerdy Explanation Slide 16 Slide 17 Slide 18 pH Indicates the acidity [H 3 O + ] of the solution pH = - log [H 3 O + ] From the French pouvoir hydrogene (hydrogen power or power of hydrogen) LecturePLUS Timberlake18 Slide 19 pH In the expression for [H 3 O + ] 1 x 10 -exponent the exponent = pH [H 3 O + ] = 1 x 10 -pH M LecturePLUS Timberlake19 Slide 20 pH Range: each number is 10 times more concentrated H+ than the number above it 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Neutral [H + ] > [OH - ] [H + ] = [OH - ] [OH - ] > [H + ] LecturePLUS Timberlake20 Acidic Basic Slide 21 Some [H 3 O + ] and pH [H 3 O + ] pH 1 x 10 -5 M 5 1 x 10 -9 M 9 1 x 10 -11 M 11 LecturePLUS Timberlake21 Slide 22 pH of Some Common Acids gastric juice1.0 lemon juice2.3 vinegar2.8 orange juice3.5 coffee5.0 milk6.6 LecturePLUS Timberlake22 Slide 23 pH of Some Common Bases blood 7.4 tears 7.4 seawater 8.4 milk of magnesia10.6 household ammonia11.0 LecturePLUS Timberlake23 Slide 24 Learning Check A. The [H 3 O + ] of tomato juice is 1 x 10 -4 M. What is the pH of the solution? 1) - 42)43)8 B. The [OH - ] of an ammonia solution is 1 x 10 -3 M. What is the pH of the solution? 1) 32)113)-11 LecturePLUS Timberlake24 Slide 25 Learning Check A. The [H 3 O + ] of tomato juice is 1 x 10 -4 M. What is the pH of the solution? 1) - 42)43)8 B. The [OH - ] of an ammonia solution is 1 x 10 -3 M. What is the pH of the solution? 1) 32)113)-11 LecturePLUS Timberlake25 Slide 26 Learning Check The pH of a soap is 10. What is the [H 3 O + ] of the soap solution? 1) 1 x 10 - 4 M 2) 1 x 10 10 M 3) 1 x 10 - 10 M LecturePLUS Timberlake26 Slide 27 Solution K w = [H 3 O + ][OH - ] = 1.0 x 10 14 A. [H3O+] = 1.0 x 10 -14 1.0 x 10-10 [OH - ] = 10 -4 or pH 4 LecturePLUS Timberlake27 Slide 28 Buffers solution in which the pH of the solution is "resistant" to small additions of either a strong acid or strong base. Slide 29 Buffer Animation Carbonic acid is a good blood buffer Slide 30 Buffer exampls Slide 31 Where are buffers used? chemical research, biological research industry Your body uses buffers to maintain a blood pH of 7.35-7.45, massive number of biochemical reactions involving enzymes. Slide 32 Acid Rain Unpolluted rain has a pH of 5.6 Rain with a pH below 5.6 is acid rain CO 2 in the air forms carbonic acid CO 2 + H 2 O H 2 CO 3 Adds to H + of rain H 2 CO 3 H + (aq) + HCO 3 -(aq) LecturePLUS Timberlake32 Slide 33 Formation of acid rain: 1. Emission of sulfur and nitrogen oxides SO2 26 million tons in 1980 NO and NO2 22 million tons in 1980 Mt. St Helens (1980) 400,000 tons SO2 Slide 34 Sources of Acid Rain Power stations Oil refineries Coal with high S content Car and truck emissions Bacterial decomposition, and lighting hitting N 2 LecturePLUS Timberlake34 Slide 35 Slide 36 2. Reactions in the atmosphere form SO3 2SO2 + O2 2 SO3 3. Reactions with atmosphere water form acids SO3 + H2O H2SO4 sulfuric acid NO + H2O NO2 nitrous acid HNO2 + H2O HNO3 nitric acid Slide 37 Effects of Acid Rain Leaches Al from soil, which kills fish Fish kills in spring from runoff due to accumulation of large amounts of acid in snow Dissolves waxy coatings that protect leaves from bacteria Corrodes metals, textiles, paper and leather LecturePLUS Timberlake37 Slide 38 Criteria Air Pollutants: NO x and SO x 200+ now-fishless lakes in Adirondacks Little Echo Pond, Franklin, NY pH = 4.2 Thousands of lakes in Canada (Ontario, Quebec, New Brunswick) now- fishless http://www.elmhurst.edu/~chm/vchembook/194acidraineffects.html Slide 39 pH Scale Matching Quia - The pH Scale Write the order you think these are from pH 1-14. Slide 40 1 Stomach Fluids 7 Pure Water 11 Rolaids, Tums 13 Bleach 2 Lemon Juice 5 Coffee 3 Vinegar 8 Blood 10 Borax 14 Lye 4 Tomatoes 6 Milk 9 Baking Soda 12 Household Ammonia Slide 41 Slide 42 ACID RAIN MOVIE Acid Rain - Our Changing Planet UMAC When precipitation goes below pH 5.6. Comes from burning of fossil fuels (cars, factories, airplanes). Sulfur and nitric oxides form sulfuric acid and nitric acid. Slide 43 Main Pollutant of Acid Rain Slide 44 Forest Destroyed by Acid Rain Slide 45 Canada U.S. Slide 46 Not just in US. China Guangzhou Shajiao on the Pearl River India Korba England Slide 47 Effects on Wildlife Generally, the young of most species are more sensitive to environmental conditions than adults. At pH 5, most fish eggs cannot hatch. At lower pH levels, some adult fish die. Some acid lakes have no fish. Slide 48 Young fish Wuhan dead fish (China) Slide 49 Slide 50 Slide 51 Acid Rain Stream Slide 52 Slide 53 Norilsk, in Russia's remote Artic region, is accused of being world's largest producer of acid rain.